Positive commandment · Mitzvat Aseh #38 of 613
For a High Priest to marry a virgin
להיות כהן גדול נושא בתולה
The verse · Vayikra 21:13
וְהוּא אִשָּׁה בִבְתוּלֶיהָ יִקָּח
“And he shall take a wife in her virginity.”
The Rambam’s words
For a High Priest to marry a virgin, as [Leviticus 21:13] states: "And he shall marry a woman who is a virgin."
להיות כהן גדול נושא בתולה, שנאמר: "וְהוּא אִשָּׁה בִּבְתוּלֶיהָ יִקָּח" (ויקרא כא, יג).
Why · Sefer HaChinuch #272
A high priest to marry a virgin maiden
“It is from the roots of the commandment [that it is] since the essence of good in a person is that he have thoughts of purity and cleanliness — for after the thoughts are the deeds of bodies drawn.”
Who & when
“And [it] is practiced in the Land at the time of the [Temple] and the service; as the high priest is appointed there, not in another place.”
Where in the Mishneh Torah
Hilchot Forbidden Intercourse הלכות איסורי ביאה