Sahih Bukhari
To make the Heart Tender (Ar-Riqaq)
Volume: 008 / Book Number: 076 / Hadith Number: 452
Narrated Abu Huraira:
Allah Apostle said, "If I had gold equal to the mountain of Uhud, it would not please me that anything of it should remain with me after three nights (i.e., I would spend all of it in Allah's Cause) except what I would keep for repaying debts."