一切經音義 21.97

21.97

須夜摩（須善也夜摩時也言彼諸天光明赫奕晝夜不別但看花開合以分其時既時非明暗之故曰善時天）。

Suyāma (須夜摩: 'su' means good; 'yāma' means time. The radiance of those devas is blazing, so day and night are indistinguishable; they divide the time only by observing the opening and closing of flowers. Since time is neither bright nor dark, it is called the Good Time Heaven [Suyāma]).