A biography for The Bhagavad Gitahasn’t been written yet.
“If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the Mighty One... I am become Death, the Shatterer of Worlds.”
“Shutting out all external objects, fixing the vision between the eyebrows, making even the inward and outward breaths, the sage who has controlled the senses, mind and understanding, who is intent upon liberation, who has cast away desire, fear and anger, he is ever freed.”
“For him who has conquered the min, the mind is the best of friends; but for one who has failed to do so, his mind will remain the greatest enemy. SB 6.6”