। ॥ १३५ ॥
In plain words
He is the one who knows every flicker of the mind, every stirring of the ego, every act the body and senses and breath perform -- the way fire seems to move when it is really the glowing iron that moves. But he himself never acts. He never changes. Not even slightly.
Close to the Sanskrit
The knower of the modifications of mind and ego-sense, and of the actions performed by body, senses, and vital breath -- following them like fire pervading iron -- neither acts nor undergoes any change at all.