Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 43

Sanskrit:

तस्मिन्महाभागवते महाभागे महात्मनि ।हिरण्यकशिपू राजन्नकरोदघमात्मजे ॥ ४३ ॥

ITRANS:

tasmin mahā-bhāgavatemahā-bhāge mahātmanihiraṇyakaśipū rājannakarod agham ātmaje

Translation:

My dear King Yudhiṣṭhira, the demon Hiraṇyakaśipu tormented this exalted, fortunate devotee, although Prahlāda was his own son.

Purport:

When a demon like Hiraṇyakaśipu, despite his elevated position due to severe austerities, begins to tease a devotee, he begins falling down, and the results of his austerities dwindle. One who oppresses a pure devotee loses all the results of his austerities, penances and pious activities. Since Hiraṇyakaśipu was now inclined to chastise his most exalted devotee son, Prahlāda Mahārāja, his opulences began dwindling.