Returning Salam While Urinating ? Sunan Abi Dawud 17

Arabic hadith text
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنِ الْحَسَنِ، عَنْ حُضَيْنِ بْنِ الْمُنْذِرِ أَبِي سَاسَانَ، عَنِ الْمُهَاجِرِ بْنِ قُنْفُذٍ، أَنَّهُ أَتَى النَّبِيَّ صلى الله عليه وسلم وَهُوَ يَبُولُ فَسَلَّمَ عَلَيْهِ فَلَمْ يَرُدَّ عَلَيْهِ حَتَّى تَوَضَّأَ ثُمَّ اعْتَذَرَ إِلَيْهِ فَقَالَ ‏"‏إِنِّي كَرِهْتُ أَنْ أَذْكُرَ اللَّهَ عَزَّ وَجَلَّ إِلاَّ عَلَى طُهْرٍ ‏"‏ ‏.‏ أَوْ قَالَ ‏"‏ عَلَى طَهَارَةٍ ‏"
Translation
Narrated Muhajir ibn Qunfudh

Muhammad bin Al-Muthanna narrated to us: 'Abd Al-A'la narrated to us: Sa'id narrated to us, from Qatadah, from Al-Hasan, from Hudhayn bin Al-Mundhir Abu Sasan, from Al-Muhajir bin Qunfud, that he came to the Prophet (ﷺ) while he was urinating. He greeted him with peace, but the Prophet (ﷺ) did not return the greeting until he performed ablution. Then he apologized to him and said: "I disliked to mention Allah, the Mighty and Sublime, except while in a state of purity" — or he said: "in a state of ablution."