It is the realm where bodhisattvas reside prior to their final human birth (in which they become a buddha). Hence, it is the realm where the Bodhisattva Svetaketu resided prior to taking rebirth in the human realm as Siddhartha Gautama. And it it is where the bodhisattva Maitreya, the future Buddha, is said to dwell.
According to the Princeton Dictionary, "many Buddhists throughout history have aspired for rebirth in the Tuṣita heaven so that they may learn from Maitreya and accompany him when he takes his final birth as a buddha."
The name Tuṣita means "contentment" or "joy." In Theravada texts, it is described as a realm of pure delight and gaiety. In the Mahayana, it is said that beings there possess the joy of the Mahayana Dharma.
In this realm, 400 human years is calculated as one day and night. The measure of their lifespan is 4000 years, where thirty such days make one month and twelve such months make one year. (This lifespan is equivalent to 576 million years in the human realm.)
According to the Dana Sutta, those who do meritorious deeds with the intention of helping others tend to be reborn in Tusita Heaven upon death.
- The Thirty-one Planes of Existence, "III. The Sensuous World (kama-loka)", Access to Insight
- Buswell & Lopez 2014, s.v. Tuṣita.
- Chim Jampaiyang 2019, Chapter 16, section "Domains in Space".
- Chim Jampaiyang 2019, s.v. Chapter 17.
- Visakhuposatha Sutta, Access to Insight
- Dana Sutta: Giving, Access to Insight
- Access to Insight editors (2013), The Thirty-one Planes of Existence , Access to Insight
- Bhikkhu Khantipalo (1996), Visakhuposatha Sutta, Access to Insight
- 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
- Tushita, Wikipedia