Bhagavad Gita 6.29
He who experiences the unity of life sees his own Self in all beings, and all beings in his own Self, and looks upon everything with an impartial eye.
सर्वभूतस्थमात्मानं सर्वभूतानि चात्मनि।
ईक्षते योगयुक्तात्मा सर्वत्र समदर्शनः॥sarvabhūtasthamātmānaṃ sarvabhūtāni cātmani|
īkṣate yogayuktātmā sarvatra samadarśanaḥ||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).