Sunan Ibn Majah 611
سنن ابن ماجه#611Da'ifIt was narrated from 'Amr bin Shu'aib from his father, that his grandfather said:"The Messenger of Allah said: 'When the two circumcised parts meet, and (the tip of the penis) disappears, then bath is obligatory
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih Lighairihi
Zubair Ali ZaiDaif
In-book reference: 1:345