Deuteronomy 26:12-15 -

On the occasion of presenting the tithes, a special service was also to be made. The tithe here referred to is the vegetable or predial tithe, which, at the end of each third year, as here prescribed, was to be converted into a gift to the poor and needy. This, properly the second tithe ( LXX ; τὸ δεύτερον ἐπιδέκατον ), but usually called the third tithe (Tobit 1:7, 8; Josephus, 'Antiq.,' 4.8, 22), is quite distinct from the Levitical tithe prescribed in Le 27:30-33 and Numbers 18:21-32 ; and it is a mistake to suppose that the law here was designed to contravene or supersede that in the earlier books. As this tithe completed the triennial series of tithes which the Israelites had to offer, it was fitting that in presenting it a solemn declaration should be made by the offerer to the effect that he had honorably and conscientiously discharged all the obligations in this respect which the Law laid upon him.