般若心経
During the Heian period, an important Sanron figure was master Chiko (709-781), whose commentary on the Heart Sutra became a classic work of Heian Buddhist scholarship and the most authoritative commentary on the Heart Sutra in the early Heian. This commentary criticized the Hosso (Yogacara) school's interpretation of the Heart Sutra, promoted the Heart Sutra as a text of definitive meaning (nītārtha) while also drawing on the work of Jizang.