Hadith 17:433
Zayd ibn al-Hubab narrated to us, he said: Jarir ibn Hazim narrated to us, he said: al-Hasan narrated to us, from al-Muhajir ibn Qunfudh, that he greeted the Messenger of Allah (may Allah bless him and grant him peace) while he was urinating, so he did not return the greeting to him until he had finished.
حدثنا زيد بن الحباب قال حدثنا جرير بن حازم قال حدثنا الحسن عن المهاجر بن قنفذ أنه سلم على رسول الله صلى الله عليه وسلم وهو يبول فلم يرد عليه حتى فرغ