Musnad Ahmad 1167:0

Asma bint Abi Bakr, may Allah be pleased with them both, said: The Messenger of Allah, peace and blessings of Allah be upon him, said to me: "Do not withhold, lest Allah withhold from you." And in another narration: "Spend, and do not count, lest Allah count against you; and do not hoard, lest Allah hoard from you."