|Positive Mitzvah Thirty-Eight
The Kohen Gadolim May Only Marry a Virgin
The Talmud states, "Rabbi Akiva held that even [the offspring of a union which was merely] contrary to a Positive Mitzvah was a bastard" (Ket. 29b in reference to Devarim 23:3). Hence, if the Kohen Gadol, who was bound by the Positive Mitzvah to marry a virgin, acted in a contrary manner, the offspring should be deemed a bastard. As an example of "contrary manner" is a case of where a Kohen Gadol who has connected with a woman who is not a virgin.
The accepted law in Yisrael today is not according to this opinion of Rabbi Akiva. A bastard is only the offspring of a union which is forbidden by a Negative Mitzvah the violation whereof entails the penalty of extinction. (Mishneh Torah, Kedushah, Hilchot Isurei Biah 15.1)
By the terms of this Mitzvah the Kohen Gadol is obligated to both take a wife and to take only a virgin as a wife. A regular Kohen is free of this obligation. Since the Kohen Gadol performed the highest priestly duties in the Sanctuary, and acted as the intermediary between G-d on the one hand and Yisrael on the other, it was essential that he should be always in a cheerful mood, and since the Divine Presence is made manifest out of abundant joyfulness and tradition states "he who has no wife lives without happiness, without blessing, and without good" (Yev. 61b), therefore the Kohen Gadol was under an obligation to be married.