Guru Padmasambhava hid many spiritual Ters (profound treasures) in Tibet, Bhutan and other parts of the Himalayan region. These treasures were to be discovered at certain times, places and under auspicious circumstances by Tertons (Treasure Revealers). The treasures comprises sacred teachings statues, or relics, which would greatly benefit sentient beings at the time of discovery.
Among the profound treasures hidden by Guru Padmasambhava in Kyichu Lhakhang were the scriptural texts of Thunderbolt Subjugation of Nagas or Namchak Ludul and the Wrathful Heart Tantric Treatise or Tumpo Thuk'kyi Gyudor.
In The King's Command Testament or Gyalpo Kayi Thangyig by Terton Orygen Lingpa (1323 - 1360), it states:
In the south of Kyichu Lhakhang, treasure texts and articles were concealed. The treasure texts of a tantra text and one sutra text were composed on paper and placed inside a copper cylinder. This was then buried inside a stone case filled with charcoal. These [texts] were laced to prevent the spiritual deterioration of the temple.
In The Lotus Testament or Pema Kathang by Terton Orygyen Lingpa, as well as in The Golden Garland Chronicles or Kathang Ser-threngma, by Terton Sangye Lingpa (1340 - 1396), it states:
Profound texts were concealed in Kyichu Lhakhang in the south. Also, between Paro Namthangkar and Dritsham, many articles of the King were concealed as treasures.
The Profound Treasure of Guru's Biography translated by Indian and Tibetan Lotsawas or Terjon Guru'i Kerab Namthar Gyabad Lotsai Gyur-jang by Terton Dorje Lingpa (1346 - 1405) mentions that there are sixteen profound treasures concealed in Kyichu Lhakhang.
Further, The Clear Mind Mirror Prophecy or Lungten Kuensel Melong by Terton Orgyen Padma Lingpa (1450 - 1521) mentions that blessed essence pills known as jangsem karma rilbu were concealed in Kyichu Lhakhang.
Terton Drukda Dorej's Terma text, The Secret Mantra for the Subjugation of the Greatest Evil Force or Tobchen Dudpung Zhompa'i Sangnag, states,
To the custodian of the monastery at Kyichu, the Great Varuna, Land of the Water Nagas, the Ters have been entrusted with truthful utterances. The treasures must be guarded by the Great Water Naga King. If the Ters are used by the faithless, the blood in their hearts will thus boil.
The Profound Treasure of Guru's Biography as revealed by Terton Dorje Lingpa identifies the twelve meditation places in Tibet and Bhutan that are most sacred to Guru Padmasambhava:
The three sacred meditational spaces in Tibet are Samye Chimphu, Yarlung Sheldrak, and Yerpa Daphug. The three sets [of the sacred meditation spaces] that together form the most excellent practice places are Lhasa, Samye and Thraduk: Taktsang (Bhutan), Kharchhu (Tibet) and Tag Rimochen (Bhutan); Kyichu (Bhutan), Kho-thing (Tibet) and Bumthang (Bhutan). Such places do not exist even in the most excellent of paradises. Whatever practices or prayers one undertakes in these sacred places, everything can be achieved, even as the slightest connection with these holy sites will result in one becoming part of the Vidyadharas, thus proceeding to paradise and leaving behind one's physical remains.
Source: Kyichu Lhakang: The Sacred Jewel of Bhutan by Dungchen Sangay Dorji, Supawan Pui Lamsam, Princess Ashi Kesang Choden Tashi Wangchuck
