The role Tushita plays in the biography of Buddhas is fixed and formal, part of what the tradition calls the career every Buddha follows. Before his final birth, the being who would become Gautama dwelt in Tushita; the texts narrate the five great observations by which he surveyed the world from there, choosing the continent, the country, the family, the mother and the time for his descent, and his entry into Queen Maya's womb, dreamed by her as a white elephant, is the point at which the heaven hands its resident to history.
The pattern now repeats. Maitreya, the bodhisattva who will be the next Buddha, is held to reside in Tushita at present, and the arithmetic of the heaven measures the wait: a day in Tushita equals four hundred human years, and a lifespan there runs four thousand celestial years, which the commentaries multiply out to place his coming in a remotely distant future, after the Dharma of the present Buddha has been wholly forgotten. This made Tushita the anchor of Buddhist futurism.
Aspirants from Theravada kings to Chinese pilgrims vowed rebirth there to descend with Maitreya; the scholar Xuanzang, returning from India, is recorded as directing his dying aspiration to Tushita; and cults of ascent to Maitreya's presence flourished for centuries alongside, and in rivalry with, the westward hope of Amitabha's Pure Land. The heaven of the contented is thus also the heaven of expectation, Buddhism's waiting room for the next turning of the wheel.