The sweetest moments a believer experiences is during the prayer, for when he/she engages in making humble and devout supplication to his Lord, he/she experiences peace and tranquillity in His presence. 
Indeed, it was the greatest joy for the Prophet (PBUH) who once observed, “The prayer is the source of my greatest joy.” (Sunan An-Nasaa’ee: 3940) He would even ask Bilaal t, his caller to the prayer, to call the prayer so he would experience spiritual peace and tranquillity. “Call [the people] to prayer, Bilaal,” he would say to him. “Let us be comforted by it.” (Sunan Abu Daawood: 4985) Also, whenever something distressed him, he would turn to prayer. (Sunan Abu Daawood: 1319)