The Tipiṭaka in Three Languages

Sekhiyakaṇḍa

Vinayapiṭaka · Parivāra · Vol. 8 · Section 448

[448] Out of disrespect (anādariya), teaching the Dhamma (dhammaṃ desento) to a person wearing sandals, he commits one offence (āpatti): a dukkaṭa.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 5 other places