'Abd al-Rahman b. Abu Bakra reported on the authority of his father that a person praised another person in the presence of Allah's Apostle (ﷺ), whereupon he said
Woe be to thee, you have broken the neck of your friend, you have broken the neck of your friend-he said this twice. If one of you has to praise his friend at all, he should say: I think (him to be) so and Allah knows it well and I do not know the secret of the heart and Allah knows the destined end, and I cannot testify his purity against Allah but (he appears) to be so and so.