The present volume is a facsimile edition of two ancient Sanskrit manuscripts from Tibet, which were actually used by Indian scholars and Tibetan Lotsavas for translation into Tibetan. They are valuable for the comments of the Lotsavas written in the cursive Tibetan script dbu.med on the palm-leaves themselves. The two texts are: (Vimalaprabha commentary on the Kalacakra-tantra (KT) and (ii) Pancaraksa.
The Vimalaprabha was translated into Tibetan by Somanatha of Kashmir and Ses.rab.grags the Lotsava of Hbro. It was revised by San.ston Mdo.sde.dpal and Tshul.khrims.dar (Toh.845). Somanatha went to Magadha to study the Kalacakra under Kalacakraprada Junior or Naropa. He studied the Tibetan language and went to Tibet after the death of Atisa. He had generous Tibetan patrons who subsidised his translation work in the 11 century. It is the earliest manuscript of the Vimalaprabha.
The five texts of the Pancaraksa have been treated as separate titles in the Kanjur (Toh. 558, 559, 561, 562, 563). They were translated by Ye.ses.sde with the help of Silendrabodhi, Jnanasiddhi, Sakyaprabha, Jinamitra and Danasila, during the reign of Ral.pa.can who ruled from 817 to 836. It was a period of great literary activity, when a common terminology was developed by a royal commission with eminent Indian and Tibetan scholars for the translation of complex philosophic ideas. The outcome of this historic effort was the Mahavyutpatti, which is an astounding linguistic work of transforming a primal Tibetan language into a valid literary language of Classical sophistication. The Sanskrit manuscript of the five Raksa texts reproduced here should go back to the early ninth century. It is a glorious symbol of the foundations of the literary heritage of Tibet.