Samyuktagama (Sanskrit fragments) 753.4

753.4

時，有比丘名阿梨瑟吒，詣佛所，稽首佛足，退坐一面，白佛言：「世尊！所謂甘露者。云何名為甘露？」

It was then that a monk named Ariṣṭa went to the Buddha, prostrated at his feet, and withdrew to sit at one side. He said to the Buddha, “Bhagavān, there’s the expression ‘immortal.’ What is it that’s called ‘immortal’?”