Leviticus 27:14, commentary and pictures

When a man sanctifies his house to be holy unto the Lord, the priest estimates it, whether it be good or bad, and as the priest estimates it so it stands as its value. A person or possession devoted by a vow is subject to the law's rules of valuation and redemption, with the priest's estimate determining the amount. If the one who vowed the house wishes to retain the property, he must pay its assessed value plus a fifth. The added amount makes the vow binding in practice and keeps consecrated property from being treated as ordinary property. This instruction about dedicating and valuing a house is included among the sanctuary's types.

Applied to Jephthah's vow, his daughter could be devoted to the Lord's service without being offered as a burnt offering. Human beings were not acceptable sacrifices and could be redeemed under the law. Because he did not redeem her, the vow left her devoted to the Lord and doomed to perpetual virginity.

Something devoted or set apart may be placed under a ban and given over to destruction. Anathema means a curse and a ban, properly something set apart, separated and devoted. In this sense the verse signifies absolute, irrevocable and entire separation of a person from the communion of the faithful, from the number of the living, or from the privileges of society. It signifies also the devoting of any man, animal, city or thing to be extirpated, destroyed, consumed and as it were annihilated.