In the Genesis narrative one sees how primogeniture was disregarded in the clan of Abraham. The son most suited to carry on the line of Abraham – with its attendant responsibility for transmitting the clan's unique religious belief – was acknowledged as the head of the family even if it meant passing by the firstborn; indeed even if it entailed banishing him from the household (Isaac was preferred to Ishmael, ch. 21: Jacob to Esau, ch. 27).
The terminology employed in Genesis, when compared to that of Deuteronomy 21:17, is problematic, and allowance for a degree of inconsistency in technical usage must be made. In Genesis, Jacob contends with Esau over two matters: first, the bekhorah, which Jacob secured from Esau, who despised it, in exchange for a cooked meal (Gen. 25:29–34); and second, the berakhah ("blessing") which Jacob secured by deceiving his elderly father into thinking that he was blessing Esau (Gen. 27). Of the two terms, the berakhah counted for more, probably because pronouncing the blessing was considered to be the act formally acknowledging the firstborn as the principal heir. Berakhah connotes both the blessing which is to be pronounced and the effects of the blessing, i.e., the wealth transmitted as inheritance. In Deuteronomy 21:17 the term bekhorah refers specifically to the estate rights.
Owing to his favored status, the firstborn was considered the most desirable sacrifice to a deity where human sacrifice was practiced. On the verge of a defeat, Mesha, king of Moab, sacrificed his eldest son and acknowledged successor (II Kings 3:27). In a prophetic passage, the sacrifice of the first-born is singled out as that offering which might be supposed the most efficacious for expiation (Micah 6:7). The importance of the bekhor is dramatized in the saga of the ten plagues God inflicted upon the Egyptians, the last of which struck down their firstborn (e.g., Ex. 11:5; 12:12). This serves as the etiology of the legal-cultic requirement that the male firstborn of man and beast in Israel were to be devoted to God. The Lord acquired title to Israel's firstborn, human and animal, by having spared them when he struck the firstborn of the Egyptians (Num. 3:13). The priestly tradition goes on to explain that the Levites, as a group, were devoted to cultic service in substitution for all the firstborn Israelites (Num. 3:12). This would seem to be the historicization of a situation that in fact obtained independently of the particular events surrounding the Exodus. The laws governing the redemption of the firstborn (Ex. 13:15; 34:19, Deut, 15:19) presumably derived from a cultic matrix. At one time firstborn sons were actually devoted to cultic service as temple slaves, Nazirites, and the like; subsequently other arrangements were made for supplying cultic personnel while the erstwhile sanctity of the firstborn was lifted through redemption (cf. Lev. 27:1–8, and see below). This underlies the priestly traditions of the history of the levites and their selection for cultic service.
In the case of animals, male firstlings unfit for sacrificial use because they bore *blemishes or were of types considered impure could be redeemed by paying the assessed value of the animal, plus one-fifth (Lev, 27:26–27; cf. verses 9–13; Ex. 34:20; Deut. 15:19). The restriction of the requirement to male firstlings may reflect on economic consideration: very few males were needed for breeding purposes. This consideration may also figure in the predominance of male animals as sacrificial victims generally. Devoting firstlings to the cultic establishment served as a means of providing it with revenue (Num, 18:15–18; compare Deut. 15:19–23).
[Baruch A. Levine]