The Book of the Believer · Hadith 178 (#Ḥadīth #8)
Chapter 8 | What Allah (azwj) has Forbidden a Believer to do Against a Fellow Believer
178 - وعن أبي عبد الله عليه السلام قال: ما من مؤمن يخذل أخاه وهو يقدر على نصرته، إلا خذله الله عز وجل في الدنيا والآخرة.
178. It has been reported that Abu 'Abd Allah said: Any believer that disappoints his brother while he is able to help him, Allah will desert him in the world and the hereafter.
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).