Volume 3, Book 48, Number 830:
Narrated Abu Bakra:
A man praised another man in front of the Prophet . The Prophet said to him, “Woe to you, you
have cut off your companion’s neck, you have cut off your companion’s neck,” repeating it several
times and then added, “Whoever amongst you has to praise his brother should say, ‘I think that he is
so and so, and Allah knows exactly the truth, and I do not confirm anybody’s good conduct before
Allah, but I think him so and so,’ if he really knows what he says about him.”
Volume 3 – 608 / 1700
SAHIH BUKHARI VOLUME 3 > BOOK 48: WITNESSES