Bhagavad Gita 10.20 · Aham Atma Gudakeshaअहमात्मा गुडाकेश सर्वभूताशयस्थितः।अहमादिश्च मध्यं च भूतानामन्त एव च ॥

O Gudakesa I am the soul (Pratyagatma) which exists in the hearts of all beings and I am also the source or origin, the middle or stay, and the end of all created beings. I am the birth, the life and the death of all beings. Meditate on Me as the innermost Self.Gudakesa means either coneror of sleep or thickhaired.He who is able to meditate on the Self with Abheda Bhavana (attitude of nonduality), is a qualified aspirant (Adhikari) of the first class. He who is not able to meditate on the Self should think of the Lord in those things which are mentioned below. This type of meditation is for the aspirants of the middle class.