On Yuan Chwang's Travels in India, 629–645 A.D. v2.c19.27

v2.c19.27

The pilgrim next takes us across to the south of the capital. To the south-west of the old city, he relates, was a small rocky mountain in the steep sides of which the inferior gods (kuei-shên) had made some tens of caves for Upagupta and the other arhats. Beside this mountain were the stone foundations of an old terrace, and tanks of dimpled water clear as a mirror, people from far and near called them "the holy water", and to drink or wash in the water effaced the soil of sin.