A man greeted the Prophet ﷺ with the salam while he had just relieved himself, and the Prophet ﷺ did not return his greeting until he gestured with his hand toward the wall, meaning that he performed tayammum.
حدثنا محمد بن جعفر حدثنا شعبة حدثنا سعيد عن محمد بن المنكدر عن رجل
أن رجلا سلم على النبي ﷺ وقد بال فلم يرد عليه النبي ﷺ حتى قال بيده إلى الحائط يعني أنه تيمم
Its isnad is daif, due to the anonymity of the narrator who transmitted from Abdullah bin Hanzala, and Haythami said likewise in 1/276. It has already preceded in similar wording at 20639.