مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 467
Purification
Associating with one who is defiled, and what is permitted - Section 2
وَعَن المُهَاجر بن قنفذ: أَنَّهُ أَتَى النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهُوَ يَبُولُ فَسَلَّمَ عَلَيْهِ فَلَمْ يَرُدَّ عَلَيْهِ حَتَّى تَوَضَّأ ثمَّ اعتذر إِلَيْهِ فَقَالَ: «إِنِّي كرهت أَن أذكر الله عز وَجل إِلَّا على طهر أَو قَالَ على طَهَارَة» . رَوَاهُ أَبُو دَاوُدَ وَرَوَى النَّسَائِيُّ إِلَى قَوْلِهِ: حَتَّى تَوَضَّأَ وَقَالَ: فَلَمَّا تَوَضَّأَ رَدَّ عَلَيْهِ
Al-Muhajir b. Qunfudh said that he came upon the Prophet (ﷺ) when he was passing water and saluted him, but he did not respond to the salutation till he had performed ablution. He then made his excuse to him saying, “I dislike mentioning God's name except when I am in a state of purity.” Abu Dawud transmitted it. Nasa’i transmitted it up to “till he had performed ablution” and said, “then when he had performed ablution he responded to it.”
Mishkat al-Masabih, 467صَحِيح (الألباني)