Deuteronomy 18:4

Thou shalt not delay to offer the first of thy ripe fruits, and of thy liquors: the firstborn of thy sons shalt thou give unto me.

The first of the firstfruits of thy land thou shalt bring into the house of the LORD thy God. Thou shalt not seethe a kid in his mother's milk.

Speak unto the children of Israel, and say unto them, When ye be come into the land which I give unto you, and shall reap the harvest thereof, then ye shall bring a sheaf of the firstfruits of your harvest unto the priest:

All the best of the oil, and all the best of the wine, and of the wheat, the firstfruits of them which they shall offer unto the LORD, them have I given thee. And whatsoever is first ripe in the land, which they shall bring unto the LORD, shall be thine; every one that is clean in thine house shall eat of it. Every thing devoted in Israel shall be thine. Every thing that openeth the matrix in all flesh, which they bring unto the LORD, whether it be of men or beasts, shall be thine: nevertheless the firstborn of man shalt thou surely redeem, and the firstling of unclean beasts shalt thou redeem. And those that are to be redeemed from a month old shalt thou redeem, according to thine estimation, for the money of five shekels, after the shekel of the sanctuary, which is twenty gerahs. But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savor unto the LORD. And the flesh of them shall be thine, as the wave breast and as the right shoulder are thine. All the heave offerings of the holy things, which the children of Israel offer unto the LORD, have I given thee, and thy sons and thy daughters with thee, by a statute for ever: it is a covenant of salt for ever before the LORD unto thee and to thy seed with thee. And the LORD spake unto Aaron, Thou shalt have no inheritance in their land, neither shalt thou have any part among them: I am thy part and thine inheritance among the children of Israel. And, behold, I have given the children of Levi all the tenth in Israel for an inheritance, for their service which they serve, even the service of the tabernacle of the congregation. Neither must the children of Israel henceforth come nigh the tabernacle of the congregation, lest they bear sin, and die. But the Levites shall do the service of the tabernacle of the congregation, and they shall bear their iniquity: it shall be a statute for ever throughout your generations, that among the children of Israel they have no inheritance. But the tithes of the children of Israel, which they offer as an heave offering unto the LORD, I have given to the Levites to inherit: therefore I have said unto them, Among the children of Israel they shall have no inheritance.

And he hath brought us into this place, and hath given us this land, even a land that floweth with milk and honey.

Moreover he commanded the people that dwelt in Jerusalem to give the portion of the priests and the Levites, that they might be encouraged in the law of the LORD. And as soon as the commandment came abroad, the children of Israel brought in abundance the firstfruits of corn, wine, and oil, and honey, and of all the increase of the field; and the tithe of all things brought they in abundantly. And concerning the children of Israel and Judah, that dwelt in the cities of Judah, they also brought in the tithe of oxen and sheep, and the tithe of holy things which were consecrated unto the LORD their God, and laid them by heaps. In the third month they began to lay the foundation of the heaps, and finished them in the seventh month. And when Hezekiah and the princes came and saw the heaps, they blessed the LORD, and his people Israel. Then Hezekiah questioned with the priests and the Levites concerning the heaps. And Azariah the chief priest of the house of Zadok answered him, and said, Since the people began to bring the offerings into the house of the LORD, we have had enough to eat, and have left plenty: for the LORD hath blessed his people; and that which is left is this great store.