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." (IT)
English reference (IT): Vol. 1, Book 1, Hadith 590 (IT)
Arabic reference (IT): Book 1, Hadith 633 (IT)