翻譯名義集 3.97

3.97

[Indraśailaguhā] The Record of the Western Regions says: 'In the Tang language it is called the Cave of Śakra. Between the southern crags of the western peak, there is a large stone chamber, wide but not high, where the Buddha often stayed. At that time Śakra, king of the gods, wrote forty-two points of doubt on the rock to make inquiries, and the Buddha expounded and resolved them for him; the traces of this still remain.'