The Bṛhadāraṇyaka Upaniṣad says the self is to be heard of, reflected on and meditated upon. Vedānta made this a method: śravaṇa, hearing the teaching from scripture and a teacher; manana, reflecting on it until doubts are removed; and nididhyāsana, sustained contemplation until the knowledge becomes direct.
Śravaṇa, manana, nididhyāsana
Hearing, reflection and contemplation: the threefold discipline of Vedānta study.
Also: hearing, reflection and contemplation