Taking the monastic name Xuanzang, he was fully ordained as a monk in 622, at the age of twenty. The myriad contradictions and discrepancies in the texts at that time prompted Xuanzang to decide to go to India and study in the cradle of Buddhism. He subsequently left his brother and returned to Chang'an to study foreign languages and to continue his study of Buddhism. He began his mastery of Sanskrit in 626, and probably also studied Tocharian. During this time, Xuanzang also became interested in the metaphysical Yogacara school of Buddhism.