One verse

Srimad Bhagavatam 6.12.31

6.12.31

निगीर्णोऽप्यसुरेन्द्रेण न ममारोदरं गत: । महापुरुषसन्नद्धो योगमायाबलेन च ॥ ३१ ॥

nigirno ’py asurendrena na mamarodaram gatah mahapurusa-sannaddho yogamaya-balena ca

nigirnah
swallowed
api
although
asura-indrena
by the best of the demons, Vrtrasura
na
not
mamara
died
udaram
the abdomen
gatah
reaching
maha-purusa
by the armor of the Supreme Lord, Narayana
sannaddhah
being protected
yoga-maya-balena
by the mystic power that Indra himself possessed
ca
also.

The protective armor of Narayana, which Indra possessed, was identical with Narayana Himself, the Supreme Personality of Godhead. Protected by that armor and by his own mystic power, King Indra, although swallowed by Vrtrasura, did not die within the demon’s belly.