When a bullock, or a sheep, or a goat, is brought forth,.... Those three are only mentioned, because they were only made use of in sacrifice, to which this law refers:then it shall be seven days under the dam; whether a calf, or a lamb, or a kid of the goats; it was not to be taken from its dam and killed, either for food or sacrifice, before it was seven days old: Fagius says, the Hebrews give two reasons why a creature might not be offered before the eighth day; one is, that a sabbath might pass over it, nothing being perfect and consistent without it, that giving, as they say perfection and consistence to all the things of the world; and the other, as the heavens and the earth being perfected in seven days, a creature which lives so long seems to be, as it were, perfect; but he observes, if we inquire after the mystical sense of it, a better reason is to be given, namely, that Christ, the type of all the sacrifices, was not to be offered, or suffer death in his infancy, which Herod contrived, but at man's estate; and to show that no man is fit to be a propitiatory sacrifice, through weakness and inability, being unable to stand before the justice of God, only Christ, in whom is perfection of strength:and from the eighth day and thenceforth it shall be accepted for an offering made by fire unto the Lord; become an acceptable burnt offering to God; so Pliny says, that the young of sheep are fit for sacrifice on the eighth day, and of an ox on the thirtieth day; see Ex 22:30.
Tzerer Hammor, fol. 104. 2. Nat. Hist. l. 8. c.