I’m going to copy some articles on this subject, but let me give you my summation of all of them. In the Old Testament, the firstborn son was the one who normally received a double inheritance, and was the one who would inherit his father’s role as head of the family. God sometimes reversed this order, as he did with Jacob and Esau (Genesis 25:21-26), and as Jacob later did with Ephraim and Manasseh (Genesis 48:13-22). Reuben was the firstborn of Jacob, but his rights as the firstborn were taken away because of his sin (Genesis 35:22; 49:3-4).
The term firstborn therefore has two main meanings. The first is more literal, referring to the fact that this son is the first son to be born of his father. The second meaning refers to the rights and authority of a person, because they are the firstborn. Our Lord is the “firstborn” in several ways, as one of the attached articles indicates. But most of all He is the One who has been appointed by God to be in authority over all things (Colossians 1:13-23; especially verses 15, 18).
Closely related is the expression “son” (which you see in 2 Samuel 7:14; Psalm 2:7-9 [compare Psalm 110:1-3]; Hebrews 1:5-14). I understand the expressions, “Thou art My Son, Today I have begotten Thee” (Hebrews 1:5a) and “I will be a Father to Him, And He shall be a Son to Me” (Hebrews 5b) to be synonymous. This speaks not of the birth of our Lord (as though this were when He came into existence - for He is eternal as John 1:1-3 indicate), but of His installation as King of the earth by His Father.
furst-be-got’-’-n (prototokos): This Greek word is translated in two passages in the King James Version by “first-begotten” (Heb 1:6; Rev 1:5), but in all other places in the King James Version, and always in the Revised Version (British and American), by “firstborn.” It is used in its natural literal sense of Jesus Christ as Mary’s firstborn (Lk 2:7; Mt 1:25 the King James Version); it also bears the literal sense of Jesus Christ as Mary’s firstborn (Lk 2:7; Mt 1:25 the King James Version); it also bears the literal sense of the firstborn of the firstborn of men and animals (Heb 11:28). It is not used in the New Testament or Septuagint of an only child, which is expressed by monogenes (see below).
Metaphorically, it is used of Jesus Christ to express at once His relation to man and the universe and His difference from them, as both He and they are related to God. The laws and customs of all nations show that to be “firstborn” means, not only priority in time, but a certain superiority in privilege and authority. Israel is Yahweh’s firstborn among the nations (Ex 4:22; compare Jer 31:9). The Messianic King is God’s firstborn Septuagint prototokos), “the highest of the kings of the earth” (Ps 89:27). Philo applies the word to the Logos as the archetypal and governing idea of creation. Similarly Christ, as “the firstborn of all creation” (Col 1:15), is not only prior to it in time, but above it in power and authority. “All things have been created through him, and unto him” (Col 1:16). He is “sovereign Lord over all creation by virtue of primo-geniture” (Lightfoot). It denotes His status and character and not His origin; the context does not admit the idea that He is a part of the created universe. So in His incarnation He is brought into the world as “firstborn,” and God summons all His angels to worship Him (Heb 1:6). In His resurrection He is “firstborn from the dead” (Col 1:18) or “of the dead” (Rev 1:5), the origin and prince of life. And finally He is “firstborn among many brethren” in the consummation of God’s purpose of grace, when all the elect are gathered home. Not only is He their Lord, but also their pattern, God’s ideal Son and men are “foreordained to be conformed to (his) image” (Rom 8:29). Therefore the saints themselves, as growing in His likeness, and as possessing all the privileges of eldest sons, including the kingdom and the priesthood, may be called the “church of the firstborn who are enrolled in heaven” (Heb 12:23).
furst’-born, furst’-ling (bekhor; prototokos): The Hebrew word denotes the firstborn of human beings as well as of animals (Ex 11:5), while a word from the same root denotes first-fruits (Ex 23:16). All the data point to the conclusion that among the ancestors of the Hebrews the sacrifice of the firstborn was practiced, just as the firstlings of the flocks and the first-fruits of the produce of the earth were devoted to the deity. The narrative of the Moabite war records the sacrifice of the heir to the throne by Mesha, to Chemosh, the national god (2 Ki 3:27). The barbarous custom must have become extinct at an early period in the religion of Israel (Gen 22:12). It was probably due to the influence of surrounding nations that the cruel practice was revived toward the close of the monarchical period (2 Ki 16:3; 17:17; 21:6; Jer 7:31; Ezek 16:20; 23:37; Mic 6:7). Jeremiah denies that the offering of human beings could have been an instruction from Yahweh (7:31; 19:5). The prophetic conception of God had rendered such a doctrine inconceivable. Clear evidence of the spiritualization and humanization of religion among the Israelites is furnished in the replacement, at an early stage, of the actual sacrifice of the firstborn by their dedication to the service of Yahweh. At a later stage the Levites were substituted for the firstborn. Just as the firstlings of unclean animals were redeemed with money (Ex 13:13; 34:20), for the dedication of the firstborn was substituted the consecration of the Levites to the service of the sanctuary (Nu 3:11-13,15). On the 30th day after birth the firstborn was brought to the priest by the father, who paid five shekels for the child’s redemption from service in the temple (compare Lk 2:27; Mishna Bekhoroth viii.8). For that service the Levites were accepted in place of the redeemed firstborn (Nu 3:45). See note. According to Ex 22:29-31 the firstborn were to be given to Yahweh. (The firstborn of clean animals, if free from spot or blemish, were to be sacrificed after eight days, Nu 18:16 ff.) This allusion to the sacrifice of the firstborn as part of the religion of Yahweh has been variously explained. Some scholars suspect the text, but in all probability the verse means no more than similar references to the fact that the firstborn belonged to Yahweh (Ex 13:2; 34:19). The modifying clause, with regard to the redemption of the firstborn, has been omitted. The firstborn possessed definite privileges which were denied to other members of the family. The Law forbade the disinheriting of the firstborn (Dt 21:15-17). Such legislation, in polygamous times, was necessary to prevent a favorite wife from exercising undue influence over her husband in distributing his property, as in the case of Jacob (Gen 25:23). The oldest son’s share was twice as large as that of any other son. When Elisha prayed for a double portion of Elijah’s spirit, he simply wished to be considered the firstborn, i.e. the successor, of the dying prophet. Israel was Yahweh’s firstborn (Ex 4:22; compare Jer 31:9 (Ephraim)). Israel, as compared with other nations, was entitled to special privileges. She occupied a unique position in virtue of the special relationship between Yahweh and the nation. In three passages (Rom 8:29; Col 1:15; Heb 1:6), Jesus Christ is the firstborn—among many brethren (Rom 8:29); of every creature (Col 1:16). This application of the term to Jesus Christ may be traced back to Ps 89:27 where the Davidic ruler, or perhaps the nation, is alluded to as the firstborn of Yahweh.
NOTE—The custom of redeeming the firstborn son is preserved among the Jews to this day. After thirty days the father invites the “Kohen,” i.e. a supposed descendant of Aaron, to the house. The child is brought and shown to the “Kohen,” and the father declares the mother of the child to be an Israelite. If she is a “Kohen,” redemption is not necessary. The “Kohen” asks the father which he prefers, his child or the five shekels; the father answers that he prefers his son, and pays to the “Kohen” a sum equivalent to five shekels. After receiving the redemption-money, the “Kohen” puts his hands on the child’s head and pronounces the Aaronite blessing (Nu 6:22-27).
We thus conclude that in Col 1:15 the phrase proƒtotokos paseƒs ktiseoƒs is predicated of the preexistent Christ. Its thrust is to ascribe to him a primacy of status over against all of creation. This status is summarized by saying that he is God’s heir par excellence. The heirship is predicated upon his role in creation, preservation and teleology. Behind the predication lies Paul’s theological conception of Christ as the second Adam. While sovereignty is the keynote of the expression and is placed in juxtaposition with creation, one must recall the OT and intertestamental usages that demonstrate overtones of special privilege and affection when the term was used as a title. That this latter nuance is completely lacking in Col 1:15 does not follow at all. Indeed, an OT illustration suffices to guard against such a conclusion. In Gen 22:2 Isaac is styled the “beloved son,” and the ensuing narrative also informs us that it was to him that Abraham gave all that he had since Isaac was his heir (24:36; cf. 25:5). Our point is simply this: It is artificial to say that eikoƒn refers only to Christ’s relationship to the Father and proƒtotokos only to creation. Since both terms depict Jesus as the second Adam, he is thereby brought into relationship with both God the Father and creation. What does not seem to be present in Paul’s use of proƒtotokos is any notion of an “eternal generation” from the Father. This is reading back into the text the dogmatic reflections of later theologians—reflections that are legitimate but not intended by the apostle Paul’s diction.
The predication of Christ as firstborn in the NT offers a challenge to Christologies ancient and modern. One cannot help being impressed by the scope of this title. At his incarnation (Luke 2:7) Jesus is designated as Mary’s firstborn, an appellative connoting his consecration to God and possibly his rightful claim to the Davidic throne. By his glorious resurrection, in which he was victorious over sin and death, he has become the “firstborn from among the dead” (Col 1:18) and now exercises sovereign sway over his redeemed people as the “firstborn from the dead” (Rev 1:5). As the head of a new, redeemed humanity destined in the eschatological transfiguration to bear the impress of his image, he is the “firstborn among many brothers” (Rom 8:29). But the conception moves not only forward toward consummation but also, in the thought of Paul, backward into the realm of protology (Col 1:17). In Paul’s view all creation finds its reference point with respect to the “firstborn over all creation,” “the heir of all things” (Col 1:15; Heb 1:2, 6). Indeed, in the eschaton Christ is the integration point for all things (Eph 1:10). A Christology that falls short of this all-encompassing affirmation does not do justice to the Scriptural data. (Multiple, Journal of the Evangelical Theological Society, (Lynchburg, VA: JETS (Electronic edition by Galaxie Software)) 1998.)
From The New Bible Dictionary:
The Heb. root bkr, found in many Semitic languages, has the general meaning ‘(to be) early’. bÿk£o‚r, ‘first-born’ (fem. bÿk£i‚ra‚ b), is used of people and animals, cognate terms being employed for firstfruits, and the first-born son’s privileges and responsibilities are known as his ‘birthright’ (bÿk£o‚ra„h). In Gn. 25:23, the eldest son is called rab£, a description occurring elsewhere only in 2nd-millennium cuneiform texts.
The first-born was regarded as ‘the beginning of (his) strength’ (re„ásŒi‚t£i‚áo‚n—Gn. 49:3; Dt. 21:17; cf. Ps. 78:51; 105:36) and ‘the opener of the womb’ (pet£er reh£em—Ex. 13:2, 12, 15; Nu. 18:15; etc.), emphasizing both paternal and maternal lines. The pre-eminent status of first-born was also accorded to Israel (Ex. 4:22) and the Davidic line (Ps. 89:27).
The eldest son’s special position was widely recognized in the ancient Near East, though it was not usually extended to sons of concubines or slave-girls (cf. Gn. 21:9-13; Jdg. 11:1-2). The accompanying privileges were highly valued, and in the OT included a larger inheritance, a special paternal blessing, family leadership and an honoured place at mealtimes (Gn. 25:5-6; 27:35-36; 37:21ff.; 42:37; 43:33; Dt. 21:15-17). The double inheritance of Dt. 21:15-17, though apparently unknown to the Patriarchs (Gn. 25:5-6), is mentioned in several Old Babylonian, Middle Assyrian and Nuzi documents, and is alluded to elsewhere in the OT (2 Ki. 2:9; Is. 61:7).
These privileges could normally be forfeited only by committing a serious offence (Gn. 35:22; 49:4; 1 Ch. 5:1-2) or by sale (Gn. 25:29-34), though paternal preference occasionally overruled in the matter of royal succession (1 Ki. 1-2; 2 Ch. 11:22-23; cf. 1 Ch. 26:10). There is also a marked interest, especially in Genesis, in the youngest son (Jacob, Ephraim, David; cf. Isaac, Joseph), but such cases were certainly contrary to expectation (Gn. 48:17ff.; 1 Sa. 16:6ff.).
Where no sons existed, the eldest daughter took responsibility for her younger sisters (Gn. 19:30ff.). It was an Aramaean custom (Gn. 29:26), and perhaps also an Israelite one (1 Sa. 18:17-27), for the eldest daughter to be married first. A Ugaritic text mentions the transfer of birthright from the eldest to the youngest daughter.
In Israelite ritual, the first-born of man and beast had a special place. The male first-born belonged to Yahweh (Ex. 13:2; 22:29b-30; Nu. 3:13), and this was underlined by Israel’s deliverance in the final plague. Children were redeemed in the Exodus generation by the Levites (Nu. 3:40-41), and later, at a month old, by a payment of five shekels (Nu. 18:16; cf. 3:42-51). Sacrifice of human first-born is occasionally mentioned, following Canaanite practice (2 Ki. 3:27; Ezk. 20:25-26; Mi. 6:7; cf. 1 Ki. 16:34), but this was a misinterpretation of Ex. 22:29. Clean male firstlings were sacrificed (Nu. 18:17-18; Dt. 12:6, 17), while imperfect animals were eaten in the towns (Dt. 15:21-23). Male firstlings of unclean animals were redeemed (Nu. 18:15), though an ass was redeemed with a lamb or had its neck broken (Ex. 13:13; 34:20).
Bibliography. I. Mendelsohn, BASOR 156, 1959, pp. 38-40; R. de Vaux, Ancient Israel2, 1965, pp. 41-42, 442-445, 488-489; idem, Stuades in OT Sacrifice, 1964, pp. 7O-73; J. Henninger, in E. Gräf (ed.), Festschrift W. Caskel, 1968, pp. 162-183; M. Tsevat, TDOT 2, pp. 121-127. m.j.s.
Jesus was the first-born (pro„totokos) of his mother (Mt. 1:25; Lk. 2:7), a phrase which allows, but does not demand, that Mary had other, later children (cf. Mk. 6:3; *Brethren of the Lord). As such, Jesus was taken to the Temple by Mary and Joseph to be offered to God (Lk. 2:22-24); since Luke omits mention of a price being paid to redeem the child, he may have intended the incident to be regarded as the dedication of the first-born to the service of God (cf. 1 Sa. 1:11, 22, 28). Jesus is also the first-born of his heavenly Father. He is the first-born of all creation, not in the sense that he himself is a created being, but rather that as God’s Son he was his agent in creation and hence has authority over all created things (Col. 1:15-17). Similarly, he is the first-born in the new creation by being raised first from the dead, and is thus Lord over the church (Col. 1:18; Rev. 1:5). He is thus the first-born in a whole family of children of God who are destined to bear his image (Rom. 8:29). There may be an echo of Ps. 89:27 in Heb. 1:6, where God’s Son is the object of worship by the angels at his coming into the world (whether the incarnation, resurrection or second advent is meant is debatable). Finally, God’s people, both living and dead, can be described as the first-born who are enrolled in heaven, since they share the privileges of the Son (Heb. 12:23).
Bibliography. O. Eissfeldt, Erstlinge und Zehnten im Alten Testament, 1917; W. Michaelis, TDNT 6, pp. 871-881; K. H. Bartels, NIDNTT 1, pp. 667-670. i.h.m.1