O my Lord, by Your own will You appear in the various species of living entities, among animals lower than human beings as well as among the demigods, to perform Your transcendental pastimes. You are not affected by material contamination. You come just to fulfill the obligations of Your own principles of religion, and therefore, O Supreme Personality, I offer my obeisances unto You for manifesting such different forms.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
तिर्यङ्मनुष्यविबुधादिषु जीवयोनि- ष्वात्मेच्छयाऽऽत्मकृतसेतुपरीप्सया यः । रेमे निरस्तरतिरप्यवरुद्धदेह- स्तस्मै नमो भगवते पुरुषोत्तमाय
tiryaṅmanuṣyavibudhādiṣu jīvayoni- ṣvātmecchayā''tmakṛtasetuparīpsayā yaḥ | reme nirastaratirapyavaruddhadeha- stasmai namo bhagavate puruṣottamāya
SB 3.9.19