Sunan Abi Dawud 216

سنن أبي داود#216Sahih

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

We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:

Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Zubair Ali ZaiSahih Bukhari (291) Sahih Muslim (248)

In-book reference: 1:216