Musannaf Ibn Abi Shayba 9:1784

Yazid ibn Harun narrated to us, he said: Husayn al-Mu'allim narrated to us, from 'Amr ibn Shu'ayb, from his father, from his grandfather, that the Messenger of Allah (may Allah bless him and grant him peace) said: "The child is for the bed, and for the fornicator is the stone (al-athlab)." It was said: "And what is al-athlab?" He said: "The stone."