Pathikasutta 1.7.18

1.7.18

Yaṃ kho panetaṃ, sunakkhatta, maññasi acelaṃ korakkhattiyaṃ—sādhurūpo ayaṃ samaṇoti. So sattamaṃ divasaṃ alasakena kālaṃ karissati.

That naked ascetic the aristocrat of Kuru, who you imagine to be a holy man, will die of flatulence in seven days.