Charles Ellicott Commentary 2 Corinthians 8:12

"For if the readiness is there, [it is] acceptable according as [a man] hath, not according as [he] hath not." — 2 Corinthians 8:12 (ASV)

For if there be first a willing mind.—This grows out of that which ye have in the previous verse. He is expecting a sum large relatively, and not absolutely. The history of the widow’s mite, found in the Gospel of his friend St. Luke (Luke 21:1–4), was probably not unknown to him as belonging to the words of the Lord Jesus which he freely cites (Acts 20:35). He has, at all events, imbibed the spirit of its teaching from other like words.