Volume 1 · Book 8 · Hadith 468
Narrated Abu Musa: The Prophet said, "A faithful believer to a faithful believer is like the bricks of a wall, enforcing each other." While (saying that) the Prophet clasped his hands, by interlacing his fingers.
— Sahih Bukhari, Volume 1, Book 8: Prayers (Salat), Hadith #468