Nāgasutta

Suttapiṭaka · Saṁyuttanikāya · Sagāthāvaggasaṁyutta · Vol. 15 · Section 419

[419] Thus have I heard. On one occasion the Blessed One was dwelling at Uruvelā on the bank of the river Nerañjarā, at the Ajapālanigrodha (the Goatherd's Banyan Tree), newly attained to full awakening (paṭhamābhisambuddha). Now on that occasion the Blessed One was seated in the open air in the thick darkness of the night, and the rain was falling drop by drop.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place

Vol. 15 · Section 431 — Sappasutta