The Book of the Believer · Hadith 115 (#Ḥadīth #9)
Chapter 5 | The Reward of Helping a Believer, Relieving Him of Distress And Showing Him Kindness
عن مسمع قال: سمعت الصادق عليه السلام يقول: من نفس عن مؤمن كربة من كرب الدنيا، نفس الله عنه كربة من كرب الآخرة، وخرج من قبره [وهو] ثلج الفؤاد.
115.It has been related that Musmi’ said:I heard al-Sadiq saying: Whoever relieves a believer of a worldly anxiety, Allah will dispel from him a distress of the hereafter and he will come forth from his grave whilst he is delighted.”
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).