The Discourse about Revata

Thus I heard: At one time the Gracious One was dwelling near Sāvatthī, in Jeta’s Wood, at Anāthapiṇḍika’s monastery. Then at that time venerable Kaṅkhārevata Doubting Revata was sitting not far away from the Gracious One, after folding his legs crosswise, and setting his body straight, reflecting on his own purification through crossing over doubt.
The Gracious One saw venerable Kaṅkhārevata sat not far away, after folding his legs crosswise, and setting his body straight, reflecting on his own purification through crossing over doubt.
Then the Gracious One, having understood the significance of it, on that occasion uttered this exalted utterance:

“Whatever doubts there are about here or hereafter,
Understandable by oneself, or understandable by another,
The meditators give up all these,
The ardent ones living the spiritual life.”