Sunan Abi Dawud 216
سنن أبي داود#216Sahihحَدَّثَنَا 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 " .
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
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 1:216