I came to the Prophet ﷺ while he was praying and greeted him with salam, and he returned the greeting.
حدثنا عفان حدثنا حماد بن سلمة حدثنا أبو الزبير عن محمد بن علي ابن الحنفية
أتيت النبي ﷺ وهو يصلي فسلمت عليه فرد علي السلام
Its chain is sahih. Nasai narrated it, 3/5, no. 1186, but the scholars said, "It is abrogated."