Sunan an-Nasa'i 3488
سنن النسائي#3488SahihIt was narrated that Zaid bin Arqam said:"Three men were brought to 'Ali while he was in Yemen; they all had intercourse with a woman during a single menstrual cycle. He asked two of them: 'Do you affirm that this child belongs to (the third man)?' And they said: 'No.' He asked another two of them: 'Do you affirm that this child belongs to (the third man)?' And they said: 'No.' So he cast lots between them, and attributed the child to the one whom the lot fell, and obliged him to pay two-thirds of the Diyah. The Prophet was told of this, and he laughed so much that his back teeth became visible
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiHasan
In-book reference: 27:100