Wikipedia
Nididhyāsana
In Advaita Vedanta and Jnana Yoga Nididhyasana ( Sanskrit: निदिध्यासन) is profound and repeated meditation on the mahavakyas, great Upanishadic statements such as "That art Thou", to realize the identity of Atman and Brahman. It is the fourth step in the training of a sisya (disciple), consisting of preparatory practives, listening to the teachings as contained in the sruti, reflection on the teachings, and nididhyasana.