Sahih Bukhari
To make the Heart Tender (Ar-Riqaq)
Volume: 008 / Book Number: 076 / Hadith Number: 429
Narrated Abu Huraira:
I heard Allah's Apostle saying, "The heart of an old man remains young in two respects, i.e., his love for the world (its wealth, amusements and luxuries) and his incessant hope."