The Scofield Bible Commentary, by Cyrus Ingerson Scofield, [1917], at sacred-texts.com
Moreover
In 2 Corintians 8-9, the apostle sums up the Christian doctrine of giving. It may be thus summarized:
(1) It is a "grace," that is, a disposition created by the Spirit. (Co2 8:7).
(2) In contrast with the law, which imposed giving as a divine requirement, Christian giving is voluntary, and a test of sincerity and love. (Co2 8:8-12); (Co2 9:1); (Co2 9:2); (Co2 9:5); (Co2 9:7).
(3) The privilege is universal, belonging, according to ability, to rich and poor. (Co2 8:1-3); (Co2 8:12-15); (Co1 16:1); (Co1 16:2).
(4) Giving is to be proportioned to income. (Co2 8:12-14); (Co1 16:2). The Old Testament proportion was the tithe, a proportion which antedates the law. (Gen 14:20).
(5) The rewards of Christian giving are:
(a) joy. (Co2 8:2).
(b) increased ability to give in proportion to that which has been already given. (Co2 9:7-11).
(c) increased thankfulness to God. (Co2 9:12).
(d) God and the Gospel glorified. (Co2 9:13); (Co2 9:14).
willing
See (Co2 8:10-12).
(See Scofield) - (Co2 8:1).