(18) The woman also with whom man shall lie.--Better, And if a man lie with a woman, that is, even when what is specified in Leviticus 15:16 takes place in intercourse between man and woman lawfully married, it pollutes both the husband and the wife. They have accordingly both to immerse their whole bodies, and remain unclean till sundown, and were debarred from the privileges of the sanctuary during that day. Hence abstinence from conjugal intercourse was regarded as a necessary preparation for the performance of sacred duties. He who had approached his wife could not draw nigh to God (Exodus 19:15), and was not allowed to partake of sacred meals. (Comp. 1Samuel 21:5-6.) The law of pollution was not designed to put a check upon marriage, since matrimony is a Divine institution (Genesis 1:27-28; Genesis 2:21-25), but it is intended to prevent husband and wife from making an immoderate use of their conjugal life, and thus to preserve them in health and vigour by prescribing such constant purifications after it. This is probably the reason why other nations of antiquity enacted similar laws. Thus the Hindoos and the Babylonians bathed after conjugal intercourse. The Egyptian priests abstained from it when they had to perform sacred duties, and the laity were not allowed to enter the precincts of the Temple unless they submitted to ablutions. Mahommed, for the same reason, enjoins lustrations upon all the faithful before reciting their prayers.

Verse 18. - The third case of an issue (cf. Exodus 19:15; 1 Samuel 21:5; 1 Corinthians 7:5).

15:1-33 Laws concerning ceremonial uncleanness. - We need not be curious in explaining these laws; but have reason to be thankful that we need fear no defilement, except that of sin, nor need ceremonial and burdensome purifications. These laws remind us that God sees all things, even those which escape the notice of men. The great gospel duties of faith and repentance are here signified, and the great gospel privileges of the application of Christ's blood to our souls for our justification, and his grace for our sanctification.The woman also with whom man shall lie with seed of copulation,.... It seems to respect any congress of a man and woman, whether in fornication or adultery, or lawful marriage, and particularly the latter; for though marriage is honourable and holy, and carnal copulation in itself lawful, yet such is the sinfulness of nature, that as no act is performed without pollution, so neither that of generation, and by which the corruption of nature is propagated, and therefore required a ceremonial cleansing:

they shall both bathe themselves in water, and be unclean until the even; so Herodotus (f) reports, that as often as a Babylonian man lay with his wife, he had used to sit by consecrated incense, and the woman did the same: and in the morning they were both washed, and did not touch any vessel before they had washed themselves; and he says the Arabians did the like: and the same historian relates (g) of the Egyptians, that they never go into their temples from their wives unwashed; see Exodus 19:15.

(f) Clio, sive, l. 1. c. 198. (g) Euterpe, sive, l. 2. c. 64.