2,020. Prohibited Relationships Punishable Through Stoning

Hilchos Issurei Biah 1:3

Neither execution nor lashes is given unless a warning was issued, even if the violator was a Torah scholar. A warning was instituted in order to distinguish between one who violates unwittingly and one who violates intentionally.

Hilchos Issurei Biah 1:4

The prohibited relationships punishable through execution include those who are executed by stoning, those who are executed by burning, and those who are executed by strangulation. The following are punishable by stoning: relations with one’s mother, with one’s father’s wife, with one’s son’s wife – she is called his daughter-in-law, one who takes the active role with another male, a man who has relations with an animal, and a woman who has relations with an animal.