Nisargadatta MaharajJust keep in mind the feeling 'I am', merge in it, till your mind and feeling become one. By repeated attempts you will stumble on the right balance of attention and affection and your mind will be firmly established in the thought-feeling 'I am'. Whatever you think, say, or do, this sense of immutable and affectionate being remains as the ever-present background of the mind.

Nisargadatta Maharaj

Chāndogya Upaniṣad Reference Materials:

Video/Audio Lectures

Swami Paramarthananda
77 classes (~55 mins each) 1, 2, 3, 4, 5, 6, 7, 8

Swami Brahmarupananda
2 talks (~55 mins each)

Swami Viditatmananda
359 classes (~75 mins each)

02 Chhandogya Upanishad

Swami Krishnananda
21 classes (~50 mins each)

Neema Majmudar
28 classes (~90 mins each)

Rishikesh Retreat of Chandogya Upanishad class 1 part 1 by Neema Majmudar