Riyad as-Salihin 222
Abu Musa (May Allah bepleased with him) reported:
Messenger of Allah (ﷺ) said, "The relationship of the believer with another believer is like (the bricks of) a building, each strengthens the other." He (ﷺ) illustrated this by interlacing the fingers of both his hands. [Al-Bukhari and Muslim] .
وعن أبي موسى رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم ‏
"‏ المؤمن للمؤمن كالبنيان يشد بعضه بعضًا‏"‏ وشبك بين أصابعه ‏.‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏ ‏.‏