וְלֹֽא־יְחַלֵּ֥ל זַרְע֖וֹ בְּעַמָּ֑יו כִּ֛י אֲנִ֥י יְהוָ֖ה מְקַדְּשֽׁוֹ׃ (פ)
At hindi niya lalapastanganin ang kanyang lahi sa gitna ng kanyang bayan; sapagkat Ako ang Walang-Hanggan na nagpapabanal sa kanya.
Rashi
ולא יחלל זרעו NEITHER SHALL HE PROFANE HIS SEED — ,thus if he marries one of these women disqualified for a union with him his offspring (זרעו) from her becomes “profaned" (חלל) being exempted from the general law of holiness that applies to the priestly status (cf. Kiddushin 77a).
Ibn Ezra
He must not disqualify his children by having sexual relations in secret with a widow, or a divorcée. Thus far, he had only been told not to marry such women in public. After discussing the holiness of the kohanim, Scripture now lists disqualifying physical defects.
Ramban
AND HE SHALL NOT PROFANE HIS SEED AMONG HIS PEOPLE. “Thus if he married one of these women who are disqualified for him, his offspring from her becomes profaned [i.e., disqualified] from the law of the sanctity of the priesthood.” This is Rashi’s language.
The Rabbi [Rashi] thus explained the verse [before us] as a mere negation, meaning: “these shall he not take in order that he profane not his offspring.” But in the opinion of our Rabbis, this constitutes a second negative commandment. Thus they have said:54Kiddushin 78 a. “If [a High Priest or a common priest] betrothed and had intercourse with one of the women disqualified to him, he is subject to two penalties of whipping, once on account of he shall not take, and again on account of he shall not profane.” And the Rabbis have also said there: “If he has intercourse without betrothal, he is liable to whipping on account of he shall not profane.” Thus it is clear that these are two negative commandments. They have also explained there the reason why, for [mere] betrothal without [subsequent] intercourse, he is not liable to whipping, because [Scripture says: he shall not take … he shall not profane, meaning:] Why must he not take [her as his wife]? “In order that he may not profane” [his offspring, and therefore if the marriage was not consummated, and he can have no offspring from her, he is not liable merely for the betrothal]. If so, the meaning of the expression, these shall he not take, is “because I [the Eternal] admonish him against profaning his seed,” and from this statement we ourselves deduce that his offspring from one of the disqualified women is profaned, [rendered unfit for the priesthood].
The Rabbi [Rashi] thus explained the verse [before us] as a mere negation, meaning: “these shall he not take in order that he profane not his offspring.” But in the opinion of our Rabbis, this constitutes a second negative commandment. Thus they have said:54Kiddushin 78 a. “If [a High Priest or a common priest] betrothed and had intercourse with one of the women disqualified to him, he is subject to two penalties of whipping, once on account of he shall not take, and again on account of he shall not profane.” And the Rabbis have also said there: “If he has intercourse without betrothal, he is liable to whipping on account of he shall not profane.” Thus it is clear that these are two negative commandments. They have also explained there the reason why, for [mere] betrothal without [subsequent] intercourse, he is not liable to whipping, because [Scripture says: he shall not take … he shall not profane, meaning:] Why must he not take [her as his wife]? “In order that he may not profane” [his offspring, and therefore if the marriage was not consummated, and he can have no offspring from her, he is not liable merely for the betrothal]. If so, the meaning of the expression, these shall he not take, is “because I [the Eternal] admonish him against profaning his seed,” and from this statement we ourselves deduce that his offspring from one of the disqualified women is profaned, [rendered unfit for the priesthood].