Trāyastriṃśa

trāyastriṃśa (P. tāvatiṃsa; T. sum cu rtsa gsum སུམ་ཅུ་རྩ་གསུམ་; C. sanshisan/tian 三十三天/忉利天), a.k.a. Heaven of the Thirty-Three, is the second of the six deva realms of the kāmadhātu, situated on the summit of Mount Meru and presided over by thirty-three gods of whom Śakra is the chief.

Overview

The Princeton Dictionary states:

[This realm] is situated on the flat summit of Mount Meru and is inhabited by thirty-three male divinities and their attendants, presided over by the divinity Śakra, the king of the gods (Śakro devānām indraḥ). The divinities live in palaces of gold among beautiful parks and have life spans of thirty million years.

Myriad Worlds states:

The heaven known as the Thirty-three [Groups of] Gods is located on the summit of the massive Meru. The chiefs of these Thirty-three Groups are enumerated as follows: the eight gods of wealth, the two Asvins, the eleven wrathful ones, and the twelve suns. One of the twelve suns, Śakra himself, rules as the principal chief-the Powerful One-of the [Thirty-three]; the remaining thirty-two lesser chiefs are designated by the title Nearly as Powerful.

The devas of this realm are attacked by the asuras, who are jealous of their wealth and power. Thus, these devas must engage in battle with the asuras.

In this realm, 100 human years is calculated as one day and night. The measure of their lifespan is 1000 years, where thirty such days make one month and twelve such months make one year. (This lifespan is equivalent to 36 million years in the human realm.)

Central city and palace

Central city

In the middle of this realm lies the city Sudaraśana (T. grong khyer lta na sdug), translated as "Captivating City" or "Lovely-to-See”.

Ornament of Abhidharma states:

In the center of Meru’s summit is the city called Sudarśana, which is 2,500 yojanas on each side, 10,000 yojanas in circumference, and rising steeply to a height of 1.5 {or 2.5} yojanas. In essence it is gold (haima), possessing an excellent shape beautiful to behold. It has 60,000 jeweled pillars, and it is surrounded by a golden barrier 2.5 yojanas in height that is a protective wall of the four layers: gold, silver, vaiḍūrya, and crystal. It has parapets that project steeply upward and downward, and four arched bridges of the four types of precious substance. The foundation inside is variegated with 101 colors, and it sinks a little when stepped on and is pliable and light when [one’s foot] is raised. It is covered with māndārava flowers,924 and the wind scatters new flowers and removes the old. Presentation on the World states:

The powerful might of the merit of the gods

raises great winds in the divine cities

to remove withered flowers

and distribute new flowers.

Again, the divine cities are ornamented with the forms of the stars of the four varieties of precious substance, half moons, mirrors, and so on. The wall is 2.5 yojanas in height and 1.5 yojana in breadth, less one yojana above the gates because “500 guardians wearing armor and 500 yakśas in blue dress bearing weapons are stationed at each gate to protect the gods of Trāyastriṃśa.

Śakra's palace

At the center of the city of Sudaraśana lies Śakra's palace, called Vaijayanta (T. rnam par rgyal ba'i khang bzang), "Palace of Complete Victory".

Ornament of Abhidharma states:

In the center of that city there is the palace of Śakra, the lord of the gods, called Vaijayanta, 250 yojanas on each side and 1,000 yojanas in circumference. It rises steeply 4.5 yojanas above the divine city with forty pillars, eight balconies, and seven stories for each balcony. In each there are seven cymbals that welcome Śakra and remove sorrow. This is explained in Presentation on the World.

[...]

In the palace of Vaijayanta there are ponds 50 yojanas wide and 200 yojanas in circumference, as explained before. The area 20 yojanas outside the city of Sudarśana is adorned by the groves called Caitraratha to the east, Pāruṣyaka to the south, Miśrakā to the west, and Nandana to the north.

The city is surrounded by a square golden fence one yojana high, 250 yojanas on each side, and 1,000 yojanas in length. Its protecting walls, parapets, and foundations are as explained before. In the first of those, there are various chariots of precious substances. In the second, when sons of gods are seated there, their minds become coarse. In the third, sons and daughters of the gods mix and enter into various activities. In the fourth, sons and daughters of the gods take joy in and play with desirable objects.

The names of the four groves (or parks) surrounding the city are: 

1. Caitraratha vana (T. shing rta sna tshogs kyi tshal), "Grove of Various Chariots".
2. Pārusakā vana [alt. or pāruṣyaka vana] (T.rtsub 'gyur tshal), "Rugged Grove." This is a charnal ground south of the city.
3. Miśrakā vana (T. 'dres pa'i tshal), "Mixed Grove," "mixed pleasure garden," "park of various activities," etc.
4. Nandana vana (T. dga' ba'i tshal), "Pleasure Grove," "Grove of Delight," etc. This is the chief of the parks in Sudarśana city, where the resident devas of the city, headed by Śakra, go for their amusement. It owes its name to the fact that anyone who enters it becomes joyous and happy, as it offers all sorts of sense pleasures.

Wars with the asuras

Ornament of Abhidharma states:

Gods (devas) and asuras argue and fight, due to avarice and jealousy, over female āsuras and the nectar (amṛta) of the gods. At times the four kings of the asuras, such as Vemacitra and so on, come; at times, those higher come. They wear solid armor of four substances — gold, silver, vaiḍūrya, and crystal — and rise from beneath the level of the water with four army batallions bearing swords, spears, throwing spears, and bows and arrows.

Śakra sends the first of the five guardians, Nando Nāgarājā, who likes white and abides in the pleasure ocean, to enter battle, and if he prevails, the asuras are stopped. But if he does not prevail, Śakra in turn sends the second guardian, Karoṭapāṇi, then the third, Mālādhāra, then the fourth, Sādamatta, and then the fifth, the four great kings, each reinforcing the former. And if they fight, they will probably defeat the asuras, but if they cannot defeat them, the four great kings go to the land of Trāyastriṃśa and proclaim, “Ah! Powerful gods, hear this! Our five guardians cannot defeat the asuras in battle: [make this known on the terraces of Meru]." Then Śakra, the lord of the gods, commands the gods of Trāyastriṃśa to enter the war.

{He thinks of the elephant Airāvata, and Airāvata and his retinue come from Jambudvīpa. They come manifesting thirty-two heads and seven tusks for each head, seven ponds, seven lotuses, seven devaputras, seven servants, and seven cymbals. They are ridden by Indra and Viṣṇu aggressively through the city, and through that aggressive behavior they become mentally and physically aggressive. The four army batallions assemble with the resolution to fight the battle and brandish four types of weapons and armor and fight to the south of Meru. Those who are to be defeated fight three times, and in the place where they are to be defeated they grow cold, the gate is closed, and they become terrified.}

If at that time the asuras are victorious, they pursue the gods into the city of Sudarśana. {Then weapons and dismembered corpses fall into the ocean, and the blood of dead beings colors the ocean. Since just how the war will progress appears in the All-Seeing lake of the garland of stars, so relatives of the dead asuras mourn even before the war stops. This is explained in the Foundations of Mindfulness Sūtra.}

If the gods win, they pursue the asuras up to the first pleasure ocean. {The drum proclaims: The gods have won, the asuras have been defeated, the animals have been put to flight and terrorized,” and the asuras return to their own abode.} If their heads or waists are severed, they die. If their major or minor limbs are severed, they grow back again.

Visits by Gautama Buddha and Maudgalyayana

According to texts of the Pali Abhidharma, Gautama Buddha visited the Trāyastriṃśa in order to teach the Abhidharma to his mother.

The Princeton Dictionary states:

The heaven is commonly mentioned in Buddhist texts. In the seventh year after his enlightenment, after performing the Śrāvastī miracles, the Buddha magically traveled to the heaven of the thirty-three, where he spent the three months of the rains retreat (varṣā) teaching the Abhidharma to his mother Māyā. (She had descended to meet him there from her abode in the Tuṣita heaven, where she had been reborn as a male deity after her death as Queen Māyā.) At the conclusion of his teaching, the Buddha made his celebrated return to earth from the heaven on a bejeweled ladder provided by Śakra, descending at the city of Sāṃkāśya.

The Buddha's disciple Maudgalyāyana also made numerous visits to this realm in order to learn about the virtuous deeds which resulted in rebirth there.

Sources

• Buswell, Robert E.; Lopez, Donald S. (2014), The Princeton Dictionary of Buddhism, Princeton University 
• Chim Jampaiyang (2019), Jinpa, Thupten, ed., Ornament of Abhidharma: A Commentary on Vasubandhu's Abhidharmakosa, translated by Coghlan, Ian James (Apple Books ed.), Library of Tibetan Classics 
• Jamgön Kongtrul (2003), Myriad Worlds, The Treasury of Knowledge, Book One, Snow Lion