C. F. Keil and Franz Delitzsch on Leviticus 21:7

Lev 21:7

Their marriage and their domestic life were also to be in keeping with their holy calling. They were not to marry a whore (i.e., a public prostitute), or a fallen woman, or a woman put away (divorced) from her husband, that is to say, any person of notoriously immoral life, for this would be irreconcilable with the holiness of the priesthood, but (as may be seen from this in comparison with Lev 21:14) only a virgin or widow of irreproachable character. She need not be an Israelite, but might be the daughter of a stranger living among the Israelites; only she must not be an idolater or a Canaanite, for the Israelites were all forbidden to marry such a woman (Exo 34:16; Deu 7:3).