A.T. Robertson Commentary 2 Corinthians 8:10

"And herein I give [my] judgment: for this is expedient for you, who were the first to make a beginning a year ago, not only to do, but also to will." — 2 Corinthians 8:10 (ASV)

Judgment (γνωμην). Deliberate opinion, but not a "command" (επιταγη verse 8). Cf. 1 Corinthians 7:25.

A year ago (απο περυσ) From last year.

Not only to do, but also to will (ου μονον το ποιησαι, αλλα κα το θελειν). Articular infinitives the objects of προενηρξασθε on which verb see verse 6). That is to say, the Corinthians promised before any others.