Sadhāyamānasutta

Evaṁ me sutaṁ— ekaṁ samayaṁ bhagavā kosalesu cārikaṁ carati mahatā bhikkhusaṅghena saddhiṁ. Tena kho pana samayena sambahulā māṇavakā bhagavato avidūre sadhāyamānarūpā atikkamanti. Addasā kho bhagavā sambahule māṇavake avidūre sadhāyamānarūpe atikkante.

So I have heard. At one time the Buddha was wandering in the land of the Kosalans together with a large Saṅgha of mendicants. Now at that time several young students were passing by not far from the Buddha in a teasing manner. The Buddha saw them.

Atha kho bhagavā etamatthaṁ viditvā tāyaṁ velāyaṁ imaṁ udānaṁ udānesi:

Then, understanding this matter, on that occasion the Buddha expressed this heartfelt sentiment:

“Parimuṭṭhā paṇḍitābhāsā, vācāgocarabhāṇino; Yāvicchanti mukhāyāmaṁ, yena nītā na taṁ vidū”ti. Navamaṁ.

“Dolts pretending to be astute, they talk, their words out of bounds. They blab at will, their mouths agape, and no one knows what leads them on.”