Scofield's Reference Notes

Moreover

In 2 Corinthians 8, 9, the apostle sums up the Christian doctrine of giving. It may be thus summarized:

(1) It is a "grace," i.e. a disposition created by the Spirit 2 Corinthians 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 2 Corinthians 8:8-12; 2 Corinthians 9:1; 2 Corinthians 9:2; 2 Corinthians 9:5; 2 Corinthians 9:7

(3) The privilege is universal, belonging, according to ability, to rich and poor 2 Corinthians 8:1-3; 2 Corinthians 8:12-15; 1 Corinthians 16:1; 1 Corinthians 16:2.

(4) Giving is to be proportioned to income 2 Corinthians 8:12-14; 1 Corinthians 16:2. The O.T. proportion was the tithe, a proportion which antedates the law Genesis 14:20.

(5) The rewards of Christian giving are (a) joy 2 Corinthians 8:2 (b) increased ability to give in proportion to that which has been already given 2 Corinthians 9:7-11 (c) increased thankfulness to God 2 Corinthians 9:12 (d) God and the Gospel glorified 2 Corinthians 9:13; 2 Corinthians 9:14

willing

See 2 Corinthians 8:10-12, (See Scofield "2 Corinthians 8:1").