Leviticus 27:1

And the LORD spake unto Moses, saying,

The opening words introduce the chapter's instructions concerning vows and tithes, namely the laws for the redemption of dedicated persons and property, including the law of tithing and how it was carried out in Israel.
The chapter concerns things set apart or devoted to the Lord, an example of anathema meaning a curse or ban and more precisely something set apart or devoted, including things devoted to destruction.

Beginning in verses 1-8 provision is made for the release or redemption of a person included in a special vow, so that a household member was to be redeemed according to the priest's valuation rather than offered as a sacrifice.
Because of this provision for release, Jephthah could have sought release from his vow rather than carrying out a human sacrifice.
Jephthah's failure to redeem his daughter shows that his vow devoted her to the Lord's service and perpetual virginity, not to death as a burnt offering, since the vow's second clause about sacrifice applied only if its object was something the law permitted as a sacrifice.

The chapter's final section explains how the law of tithing was carried out in Israel, though tithing was already known to Abraham and Jacob.