This hadeeth comes under the following chapter:
THE QUANTITY OF WATER THAT IS DESIRABLE FOR A BATH BECAUSE OF SEXUAL INTERCOURSE, BATHING OF THE MALE AND FEMALE WITH ONE VESSEL IN THE SAME CONDITION AND WASHING OF ONE OF THEM WITH THE LEFT-OVER OF THE OTHER

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا وَكِيعٌ، عَنْ مِسْعَرٍ، عَنِ ابْنِ جَبْرٍ، عَنْ أَنَسِ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يَتَوَضَّأُ بِالْمُدِّ وَيَغْتَسِلُ بِالصَّاعِ إِلَى خَمْسَةِ أَمْدَادٍ ‏.‏