Indraśailaguhā; explained by 帝釋石窟 Indra's cave; also by 蛇神山 the mountain of the snake god, also by 小孤石山 the mountain of small isolated peaks located near Nālandā, where on the south crag of the west peak is a rock cave, broad but not high, which Śākyamuni frequently visited. Indra is said to have written forty-two questions on stone, to which the Buddha replied.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous