One verse

Srimad Bhagavatam 7.5.41

7.5.41

परे ब्रह्मण्यनिर्देश्ये भगवत्यखिलात्मनि । युक्तात्मन्यफला आसन्नपुण्यस्येव सत्क्रिया: ॥ ४१ ॥

pare brahmany anirdesye bhagavaty akhilatmani yuktatmany aphala asann apunyasyeva sat-kriyah

pare
in the supreme
brahmani
absolute
anirdesye
who is not perceivable by the senses
bhagavati
the Supreme Personality of Godhead
akhila-atmani
the Supersoul of everyone
yukta-atmani
on he whose mind was engaged (Prahlada)
aphalah
without effect
asan
were
apunyasya
of a person who has no assets in pious activities
iva
like
sat-kriyah
good activities (like the performance of sacrifices or austerities)

Even though a person who has no assets in pious activities performs some good deed, it will have no result. Thus the weapons of the demons had no tangible effects upon Prahlada Maharaja because he was a devotee undisturbed by material conditions and fully engaged in meditating upon and serving the Supreme Personality of Godhead, who is unchangeable, who cannot be realized by the material senses, and who is the soul of the entire universe.