A grotto, probably near Rájagaha, where, later, a vihára, called the Kapotakondara-vihára, was built. The grotto was at one time the residence of a large number of pigeons (kapotá), hence the name (UdA.244). On one occasion Sáriputta, having recently shaved his head, was seated there wrapt in samádhi, and a yakkha, passing overhead with his friend to an assembly of yakkhas, yielded, despite the warning of his friend, to the temptation to give a knock on the monk's shining head. The yakkha immediately fell down and was swallowed up in the fires of hell. Sáriputta had but a slight headache after the blow, which was, it is said, heavy enough to crush an elephant (Ud.39f; Thag.vs.998f; PsA.494).
According to the Visuddhi-magga (p.380), Sáriputta entered into a trance at the very moment the blow was dealt him.