we learn—1. That, in the opinion of Jonathan, if a man had sexual intercourse with his brother's wife, while his brother was living, it would be a violation of the prohibition in the 16th verse;—2. That if his deceased brother had children by her, it would be unlawful for him to marry her;—and 3. That uncovering her nakedness after his decease would uncover his nakedness; because her nakedness was considered as his nakedness: "nuditas fratris tui est." There was only one exception to the general rule in the 16th verse. If a Jew died without children, his brother could lawfully marry his widow, or uncover her nakedness without offence; but in all other cases, the prohibition was binding.
That this Jewish Rabbi did not (in Levit. 20:21) refer to an adulterous connexion with a brother's wife, may be inferred from the penalty specified by him: "absque prole erunt." Such a connexion he well knew was punishable with death (Levit. 20:10); and this he notices in his comment on the verse just named, and points out the different modes of inflicting this penalty, according as the crime was committed with an espoused virgin or a married woman.