 "Vakya Vritti" is a text of fifty-two Sanskrit slokas written by Adi Shankara and is in the form of a dialogue between an eager student and an enlightened teacher.There exists a very old commentary on this text but the name of its author is not known.Swami Chinmayananda's commentary on this exhaustive exposition of the Mahavakya Tat Tvam Asi was published in 1981.