1 Corinthians 16:2
On the first day of each week let each of you put aside something, keeping it in store as he may prosper, so that when I come there may be no collections going on.
2 Corinthians 8:10
And I will give you my opinion in this matter; for this offering is fitting in your case, considering that you made a beginning before others, not only in the willingness to do something but also in actually doing something a year ago.
2 Corinthians 8:12
For if there be first willing mind, the gift is accepted according to what a man has, and not according to what he has not.
2 Corinthians 9:5-11
So I have thought that I must ask these brothers to visit you beforehand, and get your promised contribution ready in advance. I want it to be given of your bounty, not extorted from your covetousness.