Khuddakavatthukkhandhaka

Vinayapiṭaka · Cūḷavagga (2) · Vol. 7 · Section 183

[183] Now at that time the group-of-six bhikkhus were learning worldly knowledge (tiracchānavijjā) … They reported this matter to the Blessed One … "Bhikkhus, worldly knowledge is not to be learned. Whoever should learn it: an offence of wrongdoing (dukkaṭa)."

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.