大唐西域記 1.117

1.117

象堅窣堵波北山巖下有一龍泉，是如來受神飯已，及阿羅漢於中漱口嚼楊枝，因即種根，今為茂林。後人於此建立伽藍，名鞞鐸佉（唐言嚼楊枝）。

To the south-west of the town is Mount Pi-lo-sa-lo (Pilusara); the mountain spirit takes the form of an elephant, hence the name. In old days, when Tathagata was alive, the spirit, called Pilusara (siang-kien, i.e., elephant-fixed), asked the Lord of the World and 1200 Arhats (to partake of his hospitality). On the mountain is a great solid rock; here it was Tathagata received the offerings of the spirit. Afterwards Asoka-raja erected on this same rock a stūpa about 100 feet in height. It is now called the stūpa of the Elephant-strength (Pilusāra). They say that in this also is about a pint measure of the relics of Tathāgata. To the north of the Pilusāra Stūpa is a mountain cavern, below which is a Nāga fountain. It was here that Tathāgata, having received from the spirit some food (rice) with the Arhats, cleansed his mouth and rubbed his teeth with a piece of willow branch. This he planted in the ground, and it forthwith took root, and is now a bushy grove. Afterwards men built here a saṅghārāma, and called it the convent of the Pi-to-kia (the willow twig). Going eastward from this 600 li or so, across a continuation of mountains and valleys, the peaks being of a stupendous height, and skirting the "black ridge," we enter North India, and crossing the frontier, come to the country of Lan-po (Lamghān).