一切經音義 21.406

21.406

忉利天（忉利梵言正云怛唎耶怛唎奢言怛唎耶者此云三也怛唎奢者卅也謂須彌山頂四方各有八大城當中有一大城帝釋所居總數有三十三處故從處立名也）。

Trāyastriṃśa Heaven (Daoli is Sanskrit; correctly pronounced it is trayastriṃśat. Traya means three here; triṃśat means thirty. It refers to the summit of Mount Sumeru having eight great cities in each of the four directions, with one great city in the center where Śakra resides. The total number of locations is thirty-three, hence it is named after these places).