SB 6.13.16

tāvat triṇākaṁ nahuṣaḥ śaśāsa
sa sampad-aiśvarya-madāndha-buddhir
 nītas tiraścāṁ gatim indra-patnyā
tāvat — for so long; triṇākam — the heavenly planet; nahuṣaḥ — Nahuṣa; śaśāsa — ruled; vidyā — by education; tapaḥ — austerities; yoga — mystic power; bala — and strength; anubhāvaḥ — being equipped; saḥ — he (Nahuṣa); sampat — of so much wealth; aiśvarya — and opulence; mada — by the madness; andha — blinded; buddhiḥ — his intelligence; nītaḥ — was brought; tiraścām — of a snake; gatim — to the destination; indra-patnyā — by Indra’s wife Śacīdevī.
As long as King Indra lived in the water, wrapped in the stem of the lotus, Nahuṣa was equipped with the ability to rule the heavenly kingdom, due to his knowledge, austerity and mystic power. Nahuṣa, however, blinded and maddened by power and opulence, made undesirable proposals to Indra’s wife with a desire to enjoy her. Thus Nahuṣa was cursed by a brāhmaṇa and later became a snake.