Cūḷasaccakasutta
Evaṁ me sutaṁ— ekaṁ samayaṁ bhagavā vesāliyaṁ viharati mahāvane kūṭāgārasālāyaṁ.
The Shorter Discourse With Saccaka
So I have heard. At one time the Buddha was staying near Vesālī, at the Great Wood, in the hall with the peaked roof.