Charles Ellicott Commentary Ezekiel 44:22

"Neither shall they take for their wives a widow, nor her that is put away; but they shall take virgins of the seed of the house of Israel, or a widow that is the widow of a priest." — Ezekiel 44:22 (ASV)

A widow that had a priest before.—In regard both to marriage and to mourning (Ezekiel 44:25–27) the Levitical law made a broad distinction between the ordinary priest and the high priest. The former was only forbidden to marry a divorced woman (Leviticus 21:7), but was allowed to marry a widow; the latter could marry only a virgin of Israel (Leviticus 21:14).

So also in the law of mourning; the high priest might not be “defiled” nor make any sign of mourning even for his nearest of kin (Leviticus 21:11–14). Ezekiel does not recognise this distinction, and in fact nowhere mentions the high priest at all; but, instead, gives a general law for all priests, somewhat between the two.