Laws about Firstborn and Mazzoth: Exodus 13:1 f. P. Law of Firstborn. Here all are sacred to Yahweh; in J (Exodus 13:12 f., Exodus 34:19 f.) and E (Exodus 22:29 f.) all males, the ass to be redeemed with a lamb; in D male firstlings of herd and flock, to constitute a sacrificial feast for the owner and his family at the sanctuary; in P (Numbers 18:15-18, cf. Leviticus 27:26 f. P s) the firstborn of men and unclean beasts to be redeemed, of clean beasts to be sacrificed and eaten by the priests not the owner. Animal firstlings, as among other peoples, were sacrificed either simply in thankfulness for fruitfulness bestowed and expected, or with the further idea of sanctioning the use and enjoyment of later offspring. The sacredness of human firstborn (Exodus 12:29 *, Exodus 22:29 *, Numbers 3:11-13 *) followed by analogy, or, as Driver supposes (CB, p. 409f.), as the unrecognised sequel of a long-forgotten primitive practice of the actual sacrifice of the firstborn, of which the discovery at Gezer of infants buried in jars is probable evidence. [J. G. Frazer, however, thinks that they were still-born or died soon after birth, and were preserved in this way by the parents in hope that they would be re-born. He points to the absence of signs that they had been put to death. A. S. P.] An edifying justification of the custom was found in the sparing of Heb. firstborn at the Exodus. Modern study of the mysteries of heredity has lent new ground for attaching sacredness to the birth which proves the due transmission of the capacity for parentage to the individual mother. And if the first is reckoned sacred, it is not so likely that later births will be counted common. Christian tradition from the earliest times loved to tell of the Presentation of the infant Jesus in the Temple, not without symbolic sacrifice (Luke 2:23). The late idea that the Levites replaced the firstborn is found in Numbers 3:11-18 *.
Exodus 13:3-10 J (Rd). Law of Mazzoth (Exodus 13:3 Rd, Exodus 13:4 J, Exodus 13:5 Rd, Exodus 13:6 J Exodus 13:7-9 Rd, Exodus 13:10 J). Hardly any legislation can be traced to J beyond the little code in Exodus 34:14-28 which prescribes (Exodus 13:18 a) the observance of Mazzoth. But it appears that this and the next paragraph in the main belong to J, and are reproduced here to enforce their historical connexions. The verses assigned above to Rd show marks of the school of D. Possibly in part they may be due to Rje, a precursor of D. Points of comparison with P are: the old Canaanitish name for the first month, Abib, i.e. the month of the fresh young ears (Leviticus 2:14 Heb.); the hâ g or pilgrimage on the seventh not the first day; no holy convocations with enforced rest. This day ye go forth (Exodus 13:4 J) applies to the day of the Exodus: Remember this day (Exodus 13:3 Rd) enforces the later observance. For the terms of the promise and the oath in Exodus 13:5, see Exodus 3:8 * and Genesis 24:7 *, and for the stress on instruction in Exodus 13:8-14 see Exodus 12:26 *. The restriction to unleavened bread was (Exodus 13:9) to be an equivalent of the pagan practices of branding or tattooing some sacred mark on the body as a charm, or wearing some badge on the forehead (cf. p. 110, and Driver, CB). In Exodus 13:9 there is a mixture of the styles of D and P which suggests a late editor. The Heb. of Exodus 13:10 is characteristically different from Exodus 12:24.
Exodus 13:11-16 J (Rd). Law of Firstborn (Exodus 13:11-13 J, Exodus 13:14-16 Rd). On Exodus 13:11 f. see Exodus 13:3-10 *. The ass, as unclean, could neither be eaten nor sacrificed (contrast Judges 6:4 *): so its firstling must be redeemed by a lamb, less valuable, while Leviticus 27:7 prescribes a higher scale, and makes the rule general, if it be an unclean beast. Obedience to this law also was to serve (Exodus 13:16) for a badge (cf. Exodus 13:9) and for frontlets (cf. Deuteronomy 6:8 *).