Hadith 16
Narrated Ibn Umar: A man passed by the Prophet ﷺ while he was urinating, and saluted him. The Prophet ﷺ did not return the salutation to him. Abu Dawud said: It is narrated on the authority of Ibn Umar that the Prophet ﷺ performed tayammum, then he returned the salutation to the man.
Hadith 17
Narrated Muhajir ibn Qunfudh: Muhajir came to the Prophet ﷺ while he was urinating. He saluted him. The Prophet ﷺ did not return the salutation to him until he performed ablution. He then apologised to him, saying: I disliked remembering Allah except in the state of purification.