Musnad Ahmad 1531

It was narrated from ʻUmar bin Sa"d, from his father Sa"d, from the Prophet (ﷺ), that he said: “I am amazed at the situation of the Muslim: if something good befalls him, he praises his Lord and gives thanks, and if calamity strikes him, he praises his Lord and bears it with patience. The believer will be rewarded for everything, even the morsel he lifts to his mouth."