2,197. Laws of Kohanim

Hilchos Issurei Biah 16:13

It is prohibited for a Jew to direct a non-Jew to castrate his animal; if the non-Jew castrated the animal on his own, it is permitted. If a Jew uses a pretext to have his animal castrated, he is penalized by being compelled to sell the animal to another Jew. He may sell it to his own adult son but not to a minor son; he may likewise not give it to him as a gift.

Hilchos Issurei Biah 17:1

Three types of women are prohibited to all kohanim: a divorced woman, a zonah (a woman who has engaged in prohibited relations) and a chalalah (a woman of blemished kohein lineage). Four are prohibited to a Kohein Gadol: these three, plus a widow. The rules of a Kohein Gadol apply to one who was anointed with the special oil, one who wore the extra garments of a Kohein Gadol, one who served in that role, one who was appointed and removed from office, and the kohein anointed for purposes of war. All of these are must marry a virgin and may not marry a widow.