Sahih Bukhari
To make the Heart Tender (Ar-Riqaq)
Volume: 008 / Book Number: 076 / Hadith Number: 497
Narrated Abu Huraira:
Allah's Apostle said, "If anyone of you looked at a person who was made superior to him in property and (in good) appearance, then he should also look at the one who is inferior to him, and to whom he has been made superior."