Sunan Ibn Majah, Book 1, Hadith 633 (In-Book) ⓘ
It was narrated from Abu Rafi' that: The Prophet went around to all of his wives in one night, and he had a bath after each one of them. It was said to him: "O Messenger of Allah, why not make it one bath?" He said: "This is purer, better and cleaner."
حَدَّثَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، أَنْبَأَنَا عَبْدُ الصَّمَدِ، حَدَّثَنَا حَمَّادٌ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ أَبِي رَافِعٍ، عَنْ عَمَّتِهِ، سَلْمَى عَنْ أَبِي رَافِعٍ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ طَافَ عَلَى نِسَائِهِ فِي لَيْلَةٍ وَكَانَ يَغْتَسِلُ عِنْدَ كُلِّ وَاحِدَةٍ مِنْهُنَّ فَقِيلَ لَهُ يَا رَسُولَ اللَّهِ أَلاَ تَجْعَلُهُ غُسْلاً وَاحِدًا فَقَالَ " هُوَ أَزْكَى وَأَطْيَبُ وَأَطْهَرُ " .
also referenced under: Hadith 590 (Reference) & Volume 1, Book 1, Hadith 590 (DarusSalam)