The apostle here referred to the Lord’s plan for the maintenance of the priests who ministered in the temple. Those who were set apart to this holy office were supported by their brethren, to whom they ministered spiritual blessings. “Verily they that are of the sons of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people according to the law.” Hebrews 7:5. The tribe of Levi was chosen by the Lord for the sacred offices pertaining to the temple and the priesthood. Of the priest it was said, “The Lord thy God hath chosen him ... to stand to minister in the name of the Lord.” (Deuteronomy 18:5.) One tenth of all the increase was claimed by the Lord as His own, and to withhold the tithe was regarded by Him as robbery. (AA 336.1) MC VC

It was to this plan for the support of the ministry that Paul referred when he said, “Even so hath the Lord ordained that they which preach the gospel should live of the gospel.” 1 Corinthians 9:14. And later, in writing to Timothy, the apostle said, “The laborer is worthy of his reward.” 1 Timothy 5:18. (AA 336.2) MC VC

The payment of the tithe was but a part of God’s plan for the support of His service. Numerous gifts and offerings were divinely specified. Under the Jewish system the people were taught to cherish a spirit of liberality both in sustaining the cause of God and in supplying the wants of the needy. For special occasions there were freewill offerings. At the harvest and the vintage, the first fruits of the field—corn, wine, and oil—were consecrated as an offering to the Lord. The gleanings and the corners of the field were reserved for the poor. The first fruits of the wool when the sheep were shorn, of the grain when the wheat was threshed, were set apart for God. So also were the first-born of all animals, and a redemption price was paid for the first-born son. The first fruits were to be presented before the Lord at the sanctuary and were then devoted to the use of the priests. (AA 336.3) MC VC