UtshovBhagavad Gita 6.32
आत्मौपम्येन सर्वत्र समं पश्यति योऽर्जुन।
सुखं वा यदि वा दुःखं सः योगी परमो मतः।।6.32।।
Atmaupamyena sarvatra samam pashyati yorjuna
Sukham va yadi va duhkham sah yogi paramo matah
Simple meaning, written by AIO Arjuna, the one who sees all beings as equal to oneself, whether in pleasure or in pain, is considered by Me to be the highest yogi.