Sanhedrin 51 - Irrelevant Laws
" If a daughter of a Kohen starts being promiscuous, her father she profanes ..." Said Rabbi Eliezer in explanation of this, "With her father by burning; with her father-in-law by stoning."
If a daughter of a Kohen who is either betrothed or fully married commits adultery, then her punishment is correspondingly greater than that of her lover, who is punished by strangulation. But what is the meaning of Rabbi Eliezer's cryptic statement? If he meant that she commits adultery with either her father or her father-in-law, then his ruling is true even for a daughter of an Yisrael, and he did not have to state it. Rather, "with her father" means "in the domain of her father", that is, betrothed, and "with her father-in-law" means "in the domain of her father-in-law", that is, fully married.
There were other explanations, but Rav Nachman said "The law is like the first explanation." Said Rav Yosef, "The law?!? There are not capital punishments today!" Said Abaye, "Should we not learn the laws of sacrifices because they are not relevant today? We do learn them, and receive reward for learning!" And Rav Yosef meant that when the Messiah comes and resurrects the dead, we will ask Rabbi Eliezer himself.
Art: Thomas De Keyser - A Musician and His Daughter