Sunan Abi Dawud, Hadith 216 ⓘ
Abu Hurairah reported the Prophet (May peace be upon him) as saying : when anyone sits between the four parts of a woman and the parts (of the male and female) which are circumscised join together, then bath becomes obligatory.
حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ الْفَرَاهِيدِيُّ، حَدَّثَنَا هِشَامٌ، وَشُعْبَةُ، عَنْ قَتَادَةَ، عَنِ الْحَسَنِ، عَنْ أَبِي رَافِعٍ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ " إِذَا قَعَدَ بَيْنَ شُعَبِهَا الأَرْبَعِ وَأَلْزَقَ الْخِتَانَ بِالْخِتَانِ فَقَدْ وَجَبَ الْغُسْلُ " .
also referenced under: Hadith 216 (DarusSalam) & Book 1, Hadith 216 (USC-MSA)