17 And if a man take his sister, his father's daughter, or his mother's daughter, and see her nakedness, and she see his nakedness, that is a disgrace; and they shall be cut off before the eyes of the children of their people: he hath uncovered his sister's nakedness; he shall bear his iniquity. 18 And if a man shall lie with a woman in her infirmity, and uncover her nakedness, her flux doth he lay bare, and she hath uncovered the fountain of her blood; and both of them shall be cut off from among their people. 19 And the nakedness of thy mother's sister, and of thy father's sister shalt thou not uncover; for he hath laid naked his near relation: they shall bear their iniquity. 20 And if a man lie with his aunt, he hath uncovered his uncle's nakedness: their sin shall they bear: they shall die childless. 21 And if a man take his brother's wife, it is an unclean thing: he hath uncovered his brother's nakedness: they shall be childless.
Matthew Henry's Commentary on Leviticus 20:17-21
Commentary on Leviticus 20:10-27
(Read Leviticus 20:10-27)
These verses repeat what had been said before, but it was needful there should be line upon line. What praises we owe to God that he has taught the evil of sin, and the sure way of deliverance from it! May we have grace to adorn the doctrine of God our Saviour in all things; may we have no fellowship with unfruitful works of darkness, but reprove them.