Abu Dawud Book 19, Hadith Number 3659.

Narated By Anas ibn Malik : The Prophet (PBUH) said: That I sit in the company of the people who remember Allah the Exalted from morning prayer till the sun rises is clearer to me than that I emancipate four slaves from the children of Isra’il, and that I sit with the people who remember Allah from afternoon prayer till the sun sets is dearer to me than that I emancipate four slaves.