“If a man takes his sister, a daughter of his father or a daughter of his mother, and sees her nakedness, and she sees his nakedness, it is a disgrace, and they shall be cut off in the sight of the children of their people. He has uncovered his sister’s nakedness, and he shall bear his iniquity.
Sins against the seventh commandment are here ordered to be severely punished. These are sins which, of all others, fools are most apt to make a mock at; but God would teach those the heinousness of the guilt by the extremity of the punishment that would not otherwise be taught it. I. Lying with another man's wife was made a capital crime.
Commenting on Leviticus 20:10-21
And if a man shall take his sister, his father's daughter, or his mother's daughter,.... Take her to be his wife, or commit lewdness with her, whether she be his sister by both father and mother's side, or whether by one only, either way she is his sister, and it is not lawful to marry her, or lie with her, see Lev 18:9, and see...
Lev 20:9-18 Whoever cursed father or mother was to be punished with death (Lev 19:3); “His blood would be upon him.” The cursing of parents was a capital crime (see at Lev 17:4, and for the plural דּמיו Exo 22:1 and Gen 4:10), which was to return upon the doer of it, according to Gen 9:6. The same punishment was to be inflicted upon adultery (Lev 20:10, cf.
Commenting on Leviticus 20:9-18