Deuteronomy 14:23
And thou shalt eat before the LORD thy God, in the place which he shall choose to place his name there, the tithe of thy corn, of thy wine, and of thine oil, and the firstlings of thy herds and of thy flocks; that thou mayest learn to fear the LORD thy God always.
This instruction concerns the second tithe. That tithe — the tithe of grain, wine, and oil and the firstlings of herds and flocks — was to be eaten before the Lord at the place He chooses. Its stated purpose is that the people may learn to fear, honor, and reverence the Lord always.
For two years it was to be brought to the sanctuary in kind or as its value in money. After a thank-offering and a portion for the priest, the remainder was used for a religious feast at the yearly festivals. That feast was shared with Levites, strangers, orphans, and widows. It upheld worship and brought the people together with priests and Levites for instruction and encouragement in serving God.
The tithe of all increase, including produce, livestock, and the work of hand or mind, kept before the people that everything belonged to God and that they could serve as channels of His blessings. The second tithe was for the poor and other benevolent purposes. Together these tithing practices trained the people away from selfishness and toward generous, noble character.
The second tithe should not be used to support schools by providing free tuition, while missionary work in new places offers abundant opportunities for its use. The second tithe may also be used to support church-school work, including sustaining teachers.