Valmiki Ramayana Bala Kanda Sarga 10 Shloka 28
Original Shlokaतत्र चानीयमाने तु विप्रे तस्मिन्महात्मनि। ववर्ष सहसा देवो जगत्प्रह्लादयंस्तदा।।1.10.28।।
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महात्मनि when the illustrious, तस्मिन् विप्रे ascetic, आनीयमाने was being brought, तदा then, देव: Parjanya, Presiding deity for rains, जगत् earth, प्रह्लादयन् pleasing, सहसा at once, तत्र there, ववर्ष rained.
As the illustrious sage was being brought (to Anga) the god of rain (Parjanya) suddenly inundated the earth which looked cherful (with rain).