Halakha Imamat 27:2: Mishneh Torah, Positive Mitzvot & Sefer HaChinukh

That the leper shall be universally recognised as such by the prescribed marks. “His garments shall be rent and the hair of his head dishevelled and he shall cover his upper lip and shall cry ‘unclean, unclean’” (Lev. 13:45). So too, all other unclean persons should declare themselves as such.

That one who vows to the Lord the monetary value of a person shall pay the amount appointed in the Scriptural portion, as it is said, “When a man shall clearly utter a vow. .” (Lev. 27:2-8).

The commandment that one who appraises a man give the value delineated in the Torah: To rule on appraisals of people; that is, one who says, “My appraisal is upon me” or “The appraisal of x is upon me,” must give to the priest according to the amount that he said, and not less — as appears explicitly in Scripture about a male and female and according to the tally of [their] years — as it is stated (Leviticus 27:2), “If a man proclaims an oath of the appraisal of souls to the Lord.” And the matter of appraisals is included in vows of consecration and we are therefore obligated to keep them on account of “he shall not profane his words” (Numbers 30:3), “you shall not delay” (Deuteronomy 23:22) and “he shall do like everything that comes out of his mouth” (Numbers 30:3).