St. Paul on generosity (2 Cor. 9:6-8, 11-12):

Consider this: whoever sows sparingly will also reap sparingly, and whoever sows bountifully will also reap bountifully. Each must do as already determined, without sadness or compulsion, for God loves a cheerful giver. Moreover, God is able to make every grace abundant for you, so that in all things, always having all you need, you may have an abundance for every good work.

...You are being enriched in every way for all generosity, which through us produces thanksgiving to God, for the administration of this public service is not only supplying the needs of the holy ones but is also overflowing in many acts of thanksgiving to God.