The Lord speaks to Moses about someone who makes a special vow to dedicate a person to the Lord. The person is redeemed by paying a set value according to age and sex: fifty shekels of silver for a man between twenty and sixty, thirty for a woman, and smaller amounts for children and for the elderly. Someone too poor to pay presents the person to the priest, who sets the value according to what he can afford.
If the vow concerns an animal that can be offered in sacrifice, it is holy and cannot be exchanged. If it is an unclean animal, the priest values it and the owner may redeem it by adding a fifth. Something similar applies to a house or field that has been dedicated: the priest values it, and anyone who wants it back pays the value plus a fifth. Fields are valued by the seed they take and by the years remaining until the Jubilee, and they return to their owner in that year.
Firstborn animals already belong to the Lord and cannot be dedicated again, and what is devoted completely to the Lord is neither sold nor redeemed. Finally, the tithe of the land, of the seed and of the fruit, and also of the herd and flock, is holy to the Lord. Anyone who wants to redeem part of his tithe adds a fifth. So the book ends: these are the commandments the Lord gave Moses on Mount Sinai for the people of Israel.