Then the priest shall reckon unto him. — In this case the vower is not to pay the low rate fixed for a field which is the family inheritance (see Leviticus 27:16), but the priest is to value it in proportion to the number of crops which it will produce up to the year of jubile, in the same way as fields are valued in ordinary purchases. (See Leviticus 25:14-16.)
And he shall give thine estimation in that day. — This valuation the vower or his relatives had to pay all at once, without, however, the additional fifth part of its value; whilst in the case of vowing an hereditary field, the vower had the advantage of paying the small sum by yearly installments.