Sahih Muslim 327
Sahih Muslim · Book 3: The Book of Menstruation · It is recommended to pour water over the head, and elsewhere, three times
Jubair b. Mut'im reported it from the Messenger of Allah (ﷺ) that a mention was made before him about bathing because of sexual intercourse and he said:
وَ حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ ، حَدَّثَنَا شُعْبَةُ ، عَنْ أَبِي إِسْحَاقَ ، عَنْ سُلَيْمَانَ بْنِ صُرَدٍ ، عَنْ جُبَيْرِ بْنِ مُطْعِمٍ ، عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ ذُكِرَ عِنْدَهُ الْغُسْلُ مِنَ الْجَنَابَةِ فَقَالَ " أَمَّا أَنَا فَأُفْرِغُ عَلَى رَأْسِي ثَلاَثًا " .
I pour water over my head thrice.