God claimed as His possession one tenth of the seed, fruit, and livestock of the Israelites. If the owner wished to keep some of this himself, he had to pay the value of what he kept to God plus 20 percent. This tithe was a commonly recognized obligation to God and for this reason it was not part of the Mosaic Law (cf. Gen. 14:20; 28:22).310Probably Moses included the directions concerning it in this section of Leviticus because this tithe was a gift to God.
The Israelites were to devote the Sabbath entirely to God as a reminder that all their days belonged to Him. Likewise they were to tithe their income as a reminder that all their possessions belonged to Him. The tithe was not just the part the Israelites owed God. It was a reminder that they owed everything to God.311
"Lev. 27 points out that holiness is more than a matter of divine call and correct ritual. Its attainment requires the total consecration of a man's life to God's service. It involves giving yourself, your family, and all your possessions to God."312
God has given quite different directions to guide the giving of Christians under the New Covenant (cf. 1 Cor. 16; 2 Cor 8-9; Phil. 4). He has not specified a percentage that His people must give. He wants us to give joyfully, sacrificially, proportionately, and as He has prospered us. Teaching Christians to give as God instructed the Israelites under the Old Covenant often has the effect of limiting their giving rather than increasing it. Many Christians erroneously think that when they have given 10 percent they have satisfied God.