佛說處處經 1.18

1.18

「佛棄餘壽二十年，有三因緣：一者、用世間人貪身故；二者、所教已盡；三者、恐惡人誹謗之得罪重故，便取般泥洹。佛度世去，亦不持身去，亦不持意去，但為苦滅耳。地水火風空，常在世間無有斷時。

"That the Buddha relinquished twenty years of his remaining lifespan is due to three nidānas: first, because worldly people are attached to the body; second, because what was to be taught was already exhausted; third, for fear that evil people would slander him and incur heavy offenses; therefore he entered parinirvāṇa. When the Buddha departed transcending the world, he did not take his body with him, nor did he take his mind with him; it was merely the cessation of suffering. Earth, water, fire, wind, and space are constantly in the world without interruption.