The Book of the Believer · Hadith 114 (#Ḥadīth #8)
Chapter 5 | The Reward of Helping a Believer, Relieving Him of Distress And Showing Him Kindness
وعن أبي جعفر عليه السلام قال: قال رسول الله صلى الله عليه و آله وسلم: من سر مؤمنا فقد سرني، ومن سرني فقد سر الله.
114. It has been reported that Abu Ja'far said that the Messenger of Allah said:One who makes a believer happy has in fact made me happy; and one who makes me happy has in fact made Allah happy.
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).