Malik confided in me. He said, "The Prophet ﷺ confided a secret to me, and I have not informed anyone of it since. Umm Sulaym asked me about it, but I did not tell her."
أسر إلي مالك قال: أسر إلي النبي ﷺ سرا، فما أخبرت به أحدا بعده، ولقد سألتني أم سليم فما أخبرتها به.
Bukhari related it in the Book of Seeking Permission (6289), and Muslim in the Book of the Virtues of the Companions (146:2482), both of them through Mutamir bin Sulayman, who said, "I heard my father say, I heard Anas mention it," and he related it.