3. Mose 12:3

And in the eighth day - Before this time the child could scarcely be considered as having strength sufficient to bear the operation; after this time it was not necessary to delay it, as the child was not considered to be in covenant with God, and consequently not under the especial protection of the Divine providence and grace, till this rite had been performed. On circumcision see Clarke's note on Gen 17:10. Circumcision was to every man a constant, evident sign of the covenant into which he had entered with God, and of the moral obligations under which he was thereby laid. It was also a means of purity, and was especially necessary among a people naturally incontinent, and in a climate not peculiarly favorable to chastity. This is a light in which this subject should ever be viewed, and in which we see the reasonableness, propriety, expediency, and moral tendency of the ceremony.

WOMAN'S UNCLEANNESS BY CHILDBIRTH. (Lev 12:1-8) If a woman, &c.--The mother of a boy was ceremonially unclean for a week, at the end of which the child was circumcised (Gen 17:12; Rom 4:11-13); the mother of a girl for two weeks (Lev 12:5) --a stigma on the sex (Ti1 2:14-15) for sin, which was removed by Christ; everyone who came near her during that time contracted a similar defilement. After these periods, visitors might approach her though she was still excluded from the public ordinances of religion [Lev 12:4].

And in the eighth day the flesh of his foreskin shall be circumcised. Or the foreskin of his flesh, that is, of the man child born according to the law, Gen 17:12 and this seems to furnish out a reason why a male child was not circumcised before the eighth day, and why it was then, because before that its mother was in her separation and uncleanness, and then was freed from it; and so the Targum of Jonathan. The circumcision of a male child on the eighth day was religiously observed, and even was not omitted on account of the sabbath, when the eighth day happened to be on that; see Gill on Joh 7:22, Joh 7:23. It is an observation of Aben Ezra on this place, that the wise men say "in the day", and not in the night, lo, he that is born half an hour before the setting of the sun is circumcised after six days and a half, for the day of the law is not from time to time. . It is an observation of Aben Ezra on this place, that the wise men say "in the day", and not in the night, lo, he that is born half an hour before the setting of the sun is circumcised after six days and a half, for the day of the law is not from time to time. Leviticus 12:4 lev 12:4 lev 12:4 lev 12:4And she shall continue in the blood of her purifying three and thirty days,.... That is, so many more, in all forty; for though at the end of seven days she was in some respects free from her uncleanness, yet not altogether, but remained in the blood of her purifying, or in the purifying of her blood, which was more and more purified, and completely at the end of forty days: so with the Persians it is said, a new mother must avoid everything for forty days; when that time is passed, she may wash and be purified (n); and which perhaps Zoroastres, the founder of the Persian religion, at least the reformer of it,…

After the expiration of this period, on the eighth day, the boy was to be circumcised (see at Gen 17). She was then to sit, i.e., remain at home, thirty-three days in the blood of purification, without touching anything holy or coming to the sanctuary (she was not to take any part, therefore, in the sacrificial meals, the Passover, etc.), until the days of her purification were full, i.e., had expired.

After the laws concerning clean and unclean food come the laws concerning clean and unclean persons; and the first is in this chapter concerning the ceremonial uncleanness of women in child-birth (Lev 12:1-5). And concerning their purification from that uncleanness (Lev 12:6, etc.).

12:3 By the eighth day, a baby’s system has developed to a point where the blood can clot properly, rendering circumcision relatively safe.