The Lord, as Supersoul, pervades all things, just as fire permeates wood, and so He appears to be of many varieties, though He is the absolute one without a second.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
यथा ह्यवहितो वह्निर्दारुष्वेकः स्वयोनिषु । नानेव भाति विश्वात्मा भूतेषु च तथा पुमान्
yathā hyavahito vahnirdāruṣvekaḥ svayoniṣu | nāneva bhāti viśvātmā bhūteṣu ca tathā pumān
SB 1.2.32