The Price For The Redemption of a Field Of His Possession Dedicated To Yahweh (Leviticus 27:16-21).
A field of his possession refers to one the possession of which is given to him when the first share out is made in Canaan, a field which if sold would normally come back to him at the year of Yubile. To vow such a field was to seek to enter into something of the blessing of the Levite whose possession was Yahweh Himself (Joshua 13:33).
“And if a man shall sanctify to Yahweh part of the field of his possession, then your estimation shall be according to its sowing, the sowing of a homer of barley shall be valued at fifty shekels of silver.”
If the vow affects part of the field of his possession then the cost of redemption is assessed by how much grain or fruit that part of the field would produce. The assumption will be that a homer of barley would be worth fifty shekels of silver. Thus the quantity of homers of barley it might produce must be estimated in order to value the field.
“If he sanctify his field from the year of jubilee, according to your estimation it shall stand.”
If the vow is made at the beginning of the forty nine year period to the next yubile, then the assessment is made on that basis, depending on what barley could be produced in that time.
“But if he sanctify his field after the yubile, then the priest shall reckon to him the money according to the years that remain to the year of yubile; and an abatement shall be made from your estimation.”
However if the assessment is made after the year of Yubile then the proportion of time remaining is the amount which has to be taken into account.
“And if he who sanctified the field will indeed redeem it, then he shall add the fifth part of the money of your estimation to it, and it shall be assured to him.”
In the end the price that must be paid for its redemption so that it again belongs to the man whose inheritance it first was is the estimated price plus one fifth redemption offering. If that is paid then the field is again his. But now in his sight it is a blessed field, for it has belonged to Yahweh.
“And if he will not redeem the field, or if he has sold the field to another man, it shall not be redeemed any more, but the field, when it goes out in the jubilee, shall be holy to Yahweh, as a field devoted. The possession of it shall be the priest's.”
But if a man has vowed the field and will not redeem it, or if he has vowed it and sold it to someone else (and therefore cannot redeem it), then at the year of Yubile it will be holy to Yahweh and will not be able to be redeemed. From then on it is the possession of the priests.
This would seem to be the only way by which the family fields could permanently be lost. In this case they had been given back to Yahweh and were therefore irrecoverable. The man had to consider the full consequences of his vow.