One day the Messenger of Allah (May peace be upon him) had sexual intercourse with (all) his wives with a single bath. Abu Dawud said: This tradition has been transmitted through another chain of narrators.  

أَنَّ رَسُولَ اللَّهِ ﷺ طَافَ ذَاتَ يَوْمٍ عَلَى نِسَائِهِ فِي غُسْلٍ وَاحِدٍ