In Sanskrit, this text is called:
“Amrita Hridaya Angha Ashta Guhya Upadesha Tantra Nama”
in Tibetan,
“Düdtsi Nyingpo Yenlak Gyepa Sangwa Mengngak ki Gyü”,

“The Quintessence of Nectar: The Tantra of the Secret Oral Instructions on the Eight Branches of Medicine”

Homage to the conquering, transcendent Bhagavan, the Tathagata-Arhat, the enemy-conquering, perfectly and completely enlightened Medicine Buddha, King of the Vaidurya-blue Light!
Transcendent Bhagavan Conqueror, through your compassion you act on behalf of beings! Just by hearing your name, they are protected from the sufferings of the lower realms of negative rebirth! To the Medicine Buddha who eliminates disorders of the Three Poisons, to the Vaidurya-blue Light, I prostrate and pay homage.

Once, I spoke as follows, while in the abode of the rishis [sages], in that city of medicine known as Tanaduk [‘Beautiful to Behold’]. There was an immeasurable celestial palace, made of five different kinds of precious stones.
For its ornamentation, the palace was ornamented with many different types of precious medicinal jewels. These precious jewels can eliminate all four hundred and four types of disorder, [the one hundred and one] disorders of loong, [the one hundred and one] disorders of tripa, [the one hundred and one] disorders of beken, and [the one hundred and one types of] düpa or combined humor disorders. They can become cooling for tshawa or hot-natured disorders and warming for drangwa or cold-natured disorders. They can ‘pacify’ or cure the eighty thousand types of gek or obstructing forces, [they are wish-fulfilling jewels] which can accomplish all the needs and wishes [of beings], exactly as desired.

To the south of the city, there was a mountain named Mount Bikché (‘Piercer, Penetrator’) and on that mountain endowed with the force, power, or potency of the sun (nyimé top) were thick forests of all sorts of drangwa or cold-natured disorder- curing medicines with hot, sour, and salty tastes and warming and sharp potencies, like pomegranate, black pepper, long pepper, tsitraka, and so on. The roots, trunks, branches, leaves, flowers, and fruits of these medicines were deliciously fragrant, beautiful to look at, and captivating. Wherever the fragrance of these medicines spread drangwa disorders could not arise.

To the north of the city, there was a mountain called Gangchen (‘Snowy, Snow-clad’), and on that mountain endowed with the power of the moon (dawé top) were thick forests of all sorts of tshawa or hot-natured disorder-curing medicines with bitter, sweet, and astringent tastes and cooling and dulling potencies like sandalwood, camphor, agarwood, neem, and so on. The roots, trunks, branches, leaves, flowers, and fruits of these medicines were deliciously fragrant, beautiful to look at, and captivating. Wherever the fragrance of these medicines spread tshawa disorders could not arise.

To the east of the city, there was a mountain named Pö Ngeden (‘Fragrant with Incense’), and on that mountain there were thick forests of arura trees. The roots of the arura plant cure bone disorders, the trunks cure muscle disorders, the branches nerve and joint disorders, the bark skin disorders, the leaves disorders of the hollow organs, the flowers disorders of the sensory organs, and the fruits disorders of the solid organs. At the peak of the mountain, five forms of arura ripened. These were endowed with the six tastes, the eight potencies or properties, the three post-digestive tastes, and seventeen qualities. They cure every type of disease, smell delicious, are beautiful to look at, and captivating. Wherever the fragrance of these medicines spread, the four hundred and four types of disorder could not arise.

To the west of the city, there was a mountain named Malaya (‘Garlanded’), where the zangpo druk (i.e. the ‘Six Good Substances’, ‘Six Excellent Medicines’) grew. This was a mountain possessing medicinal substances capable of curing all disorders: the five kinds of medicinal calcite, the five kinds of drakzhün or shilajit, the five types of medicinal waters, and the five types of hot spring. There were hilly meadows of saffron and the fragrance of aromatic herbs [used for incense] was everywhere. Every cliff possessed every possible type of medicinal mineral and salt. In the upper canopy of the medical forests were flying creatures like peacocks, shang shang, parrots and so on, singing their beautiful bird songs. At the ground level of the forest lived every possible type of animal possessing excellent medicinal properties, like elephants, bears, musk- deer, and so on. [The mountain] was adorned with every possible type of medicine that could be grown or found.

In the center of the immeasurable, celestial palace on a jeweled, vaidurya throne, was seated the Teacher, the one known as the conquering, transcendent Bhagavan, the Great Physician and Guru of Medicine, the Medicine Buddha, the King of Vaidurya Light.
For his retinue, the Teacher was completely encircled by four groups of students: a circle or retinue of deities, of rishis, of ‘outsiders’ or non-Buddhists, and of ‘insiders’ or Buddhists.

The retinue of deities was as follows: Such ones as the deity-physicians Prajapati Daksha and Ashvini, the Lord of the Gods Indra (‘he of hundreds of offerings’), the Goddess Amrita Devi, many circles of deities all seated together.

The retinue of rishis was as follows: Such great sages as Atreya, Agnivesha, Nimindhara, Kasyapa, Carakaparivrajaka, Bharadvaja, Dhawantari, Punarvasu and so on, many circles of sages all seated together.

The retinue of non-Buddhist students was as follows: Such ones as the forefather of the non-Buddhist tirthikas Brahma, Mahadeva Sri Ralpachen, Vishnu, Kumara Shadanana (i.e. Skanda/Kartikeya] and so on, many circles of tirthikas all seated together.

The retinue of Buddhist students was as follows: Such ones as noble Manjushri, Lord Avalokiteshvara, Vajrapani, Ananda, Jivaka Kumara and so on, many circles of Buddhists all seated together.

In that moment, at that time, all four retinues of students fully heard or understood every single word spoken by the Teacher in terms of their own respective Teacher’s tradition or system [of medicine].
This [teaching of the Gyü Zhi] is called the ‘tradition or system of the sages’ because [practitioners of it first] ‘straighten out’ or rectify their own body, speech-energy, and mind to be without faults or defects then balance the [humoral] imbalances of others.

The has been the first ‘Introductory Discussion’ chapter from the ‘The Quintessence of Nectar: The Tantra of the Secret Pith or Oral Instructions on the Eight Branches [of Medicine]’.

Ch. 1, Tsa Gyü, ‘The Setting of the Scene”