續一切經音義 1.146

1.146

阿迦膩吒（梵語也具足應云阿迦尼瑟吒此譯云色究竟也言其色界十八天中此最終極也又云無小餘天互望亦大亦小此之一天唯大無小故以為名）。

阿迦膩吒 [Akaniṣṭha] (Sanskrit; fully it should be 阿迦尼瑟吒 [Akaniṣṭha]. Here it is translated as 'Culmination of Form' (Rūpapratiṣṭhā / Ultimate of the Form Realm), meaning that among the eighteen heavens of the Form Realm, this one is the ultimate pinnacle. It is also called 'Having None Smaller': when other heavens are compared against each other, they are relatively larger or smaller, whereas this single heaven is only large and has nothing smaller than it, hence its name).