Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 31
Sanskrit:
स निजं रूपमास्थाय गिरीन्द्रसदृशं बली ।इच्छन्विमोक्तुमात्मानं नाशक्नोद्ग्रहणातुर: ॥ ३१ ॥
ITRANS:
sa nijaṁ rūpam āsthāyagirīndra-sadṛśaṁ balīicchan vimoktum ātmānaṁnāśaknod grahaṇāturaḥ
Translation:
The demon changed into his original form, as big and powerful as a great mountain. But try as he might to free himself, he could not do so, having lost his strength from being held in the Lord’s tight grip.