Sahih Muslim
The Book of Zakat (Kitab Al-Zakat)
Book Number: 005 / Hadith Number: 2178
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying that Allah, the Most Blessed and High, said: O son of Adam, spend. I will spend on you. The right hand of Allah is full and overflowing and in nothing would diminish it, by overspending day and night.