This must refer to an unexpected occurrence. Intercourse during the acknowledged period was a heavy crime, and was to be punished by "cutting off" Leviticus 18:19; Leviticus 20:18; Ezekiel 18:6.

The common sense of all mankind has led them to avoid the gross impropriety referred to in this verse - and it has been a general opinion, that off-spring obtained in this way has been infected with leprous, scrofulous, and other deeply radicated diseases, from which they and their posterity have been scarcely ever freed. In Leviticus 20:18, persons guilty of this are condemned to death; here only to a seven days' separation; because, in the former case, Moses speaks of the act when both the man and woman were acquainted with the situation: in the latter, he speaks of a case where the circumstance was not known till afterwards; at least, so it appears these two places should be understood, so as to be reconciled.

And if any man lie with her at all,.... Not presumptuously but ignorantly, as Aben Ezra observes; for he was guilty of cutting off, that lay with her wilfully, Leviticus 20:18,

and her flowers be upon her; or, "her separation" (k), her monthly courses not being ceased:

he shall be unclean seven days; and be excluded from all conversation civil and religious:

and all the bed whereon she lieth shall be unclean; that and every thing upon it; and this uncleanness also lasted seven days, as Aben Ezra notes, and defiled others, though it is not written.

(k) "menstruum ejus", Pagninus, Montanus; "separatio ejus", Drusius.

If a man lay with her and her uncleanness came upon him, he became unclean for seven days, and the bed upon which he lay became unclean as well. The meaning cannot be merely if he lie upon the same bed with her, but if he have conjugal intercourse, as is evident from Leviticus 20:18 and Numbers 5:13 (cf. Genesis 26:10; Genesis 34:2; Genesis 35:22; 1 Samuel 2:22). It cannot be adduced as an objection to this explanation, which is the only admissible one, that according to Leviticus 18:19 and Leviticus 20:18 intercourse with a woman during her menses was an accursed crime, to be punished by extermination. For the law in Leviticus 20:18 refers partly to conjugal intercourse during the hemorrhage of a woman after child-birth, as the similarity of the words in Leviticus 20:18 and Leviticus 12:7 (דּמיה מקור) clearly proves, and to the case of a man attempting cohabitation with a woman during her menstruation. The verse before us, on the contrary, refers simply to the possibility of menstruation commencing during the act of conjugal intercourse, when the man would be involuntarily defiled through the unexpected uncleanness of the woman.

And if any man lie with her at all, and her flowers {h} be upon him, he shall be unclean seven days; and all the bed whereon he lieth shall be unclean.

(h) If any of her uncleanness touched him in the bed: for else the man that companied with such a woman should die, 20:18.

15:24 Seven days - If he did this ignorantly; but if the man and woman did this knowingly, being accused and convicted, they were punished with death, Lev 20:18, for as there was a turpitude in the action, so it was very prejudicial to the children then begotten, who were commonly weak, or leprous; which was also an injury to the commonwealth of Israel, and redounded to the dishonour of God and of the true religion, that the professors thereof gave such public evidence of their intemperance.

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.