First-Fruits

Boyd’s Bible Dictionary:

Were offerings and priest’s perquisites
(Ex. 22:29; 23:19; 34:2629Thou 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. (Exodus 22:29)
19The 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. (Exodus 23:19)
26The first of the firstfruits of thy land thou shalt bring unto the house of the Lord thy God. Thou shalt not seethe a kid in his mother's milk. (Exodus 34:26); Lev. 2:12; 23:10-1212As for the oblation of the firstfruits, ye shall offer them unto the Lord: but they shall not be burnt on the altar for a sweet savor. (Leviticus 2:12)
10Speak 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: 11And he shall wave the sheaf before the Lord, to be accepted for you: on the morrow after the sabbath the priest shall wave it. 12And ye shall offer that day when ye wave the sheaf an he lamb without blemish of the first year for a burnt offering unto the Lord. (Leviticus 23:10‑12); Num. 18:1212All 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. (Numbers 18:12); Deut. 18:3-43And this shall be the priest's due from the people, from them that offer a sacrifice, whether it be ox or sheep; and they shall give unto the priest the shoulder, and the two cheeks, and the maw. 4The firstfruit also of thy corn, of thy wine, and of thine oil, and the first of the fleece of thy sheep, shalt thou give him. (Deuteronomy 18:3‑4)).

Concise Bible Dictionary:

1. As God had claimed the first-born of man and beast, so also he claimed the first of the first-fruits, that they might be presented as an acknowledgment that God was the giver of them, and thanks be rendered for His gifts. All the males were to present themselves three times in the year before God, and these occasions were arranged at the times of ingathering of the barley (at the Feast of Unleavened Bread); of wheat (at the Feast of Weeks); and of the vintage (at the Feast of Tabernacles) (Ex. 23:16, 1916And the feast of harvest, the firstfruits of thy labors, which thou hast sown in the field: and the feast of ingathering, which is in the end of the year, when thou hast gathered in thy labors out of the field. (Exodus 23:16)
19The 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. (Exodus 23:19); Ex. 34:22, 2622And thou shalt observe the feast of weeks, of the firstfruits of wheat harvest, and the feast of ingathering at the year's end. (Exodus 34:22)
26The first of the firstfruits of thy land thou shalt bring unto the house of the Lord thy God. Thou shalt not seethe a kid in his mother's milk. (Exodus 34:26); Deut. 18:44The firstfruit also of thy corn, of thy wine, and of thine oil, and the first of the fleece of thy sheep, shalt thou give him. (Deuteronomy 18:4); Deut. 26:1010And now, behold, I have brought the firstfruits of the land, which thou, O Lord, hast given me. And thou shalt set it before the Lord thy God, and worship before the Lord thy God: (Deuteronomy 26:10); Ezek. 48:1414And they shall not sell of it, neither exchange, nor alienate the firstfruits of the land: for it is holy unto the Lord. (Ezekiel 48:14)).
2. Christians are said to have the first-fruits of the Spirit: they have the earnest or pledge of still future and larger blessing (Rom. 8:2323And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body. (Romans 8:23); 2 Cor. 5:55Now he that hath wrought us for the selfsame thing is God, who also hath given unto us the earnest of the Spirit. (2 Corinthians 5:5); Eph. 1:1414Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory. (Ephesians 1:14)).
3. Those first gathered to God in any economy are called the first-fruits (Rom. 11:1616For if the firstfruit be holy, the lump is also holy: and if the root be holy, so are the branches. (Romans 11:16); Rom. 16:55Likewise greet the church that is in their house. Salute my wellbeloved Epaenetus, who is the firstfruits of Achaia unto Christ. (Romans 16:5); 1 Cor. 16:1515I beseech you, brethren, (ye know the house of Stephanas, that it is the firstfruits of Achaia, and that they have addicted themselves to the ministry of the saints,) (1 Corinthians 16:15); Jas. 1:1818Of his own will begat he us with the word of truth, that we should be a kind of firstfruits of his creatures. (James 1:18); Rev. 14:44These are they which were not defiled with women; for they are virgins. These are they which follow the Lamb whithersoever he goeth. These were redeemed from among men, being the firstfruits unto God and to the Lamb. (Revelation 14:4)).
4. Christ, being raised from among the dead, is the first-fruits of them that sleep (1 Cor. 15:20, 2320But now is Christ risen from the dead, and become the firstfruits of them that slept. (1 Corinthians 15:20)
23But every man in his own order: Christ the firstfruits; afterward they that are Christ's at his coming. (1 Corinthians 15:23)). “First-fruits” necessarily imply that there are more like them to follow.