2 Corinthians 9:5, 7

So I thought it necessary to urge the brethren that they would go on ahead to you and arrange beforehand your previously promised bountiful gift, so that the same would be ready as a bountiful gift and not affected by covetousness.

Each one must do just as he has purposed in his heart, not grudgingly or under compulsion, for God loves a cheerful giver.