Tractate Sanhedrin, Herbert Danby tr. , at sacred-texts.com
M.IX. 1a. These are punishable by burning: he who has criminal connexion with a woman and her daughter, 1 and a priest's daughter 2 (who has committed adultery). The term "a woman and her daughter" includes a man's own daughter, his daughter's or son's daughter, his wife's daughter, her daughter's or son's daughter, his mother-in-law, the mother of his father-in-law, and the mother of his mother-in-law.
Although we have no express sanction from Scripture that he is to be burnt who has criminal connexion with the daughter of one who is not his legal wife--the passage in Scripture: AND THE MAN WHO SHALL TAKE (i.e. "marry") A WOMAN AND HER MOTHER, IT IS LEWDNESS, 3 dealing with actual marriage--Scripture says: AND THE DAUGHTER OF ANY MAN (OR) PRIEST, 4 to include every case.
2. A betrothed damsel and a priest's daughter who has committed adultery are to be stoned. R. Shimeon says that they are to be burnt.
114:1 Lev. 20. 54.
114:2 Lev. 21. 9.
114:3 Lev. 20. 14.
114:4 Lev. 21. 9. The two words ’ish kohen are regarded not as being in apposition, but descriptive of both classes.