首楞嚴義疏注經 9.20

9.20

王為梵主，故云統攝。戒定慧具，故云圓滿梵行。此結前也。澄心下，正明此天定心轉勝，故云澄心不動。定光明發，故云寂湛生光。二禪已上離覺觀故，無有語言，但以定心發光，以光勝劣分其位次。此天喜相初生，慧光尚劣，名少光天。

The king serves as the Brahmā lord, hence it is said, "govern." Precepts, meditative absorption, and wisdom are complete, hence it is said, "fulfill their pure conduct." This concludes what precedes. From "their settled minds" downward, it directly clarifies that in this heaven the mind of meditative absorption becomes increasingly superior, hence it is said, "their settled minds are unmoving." The radiance of meditative absorption arises, hence it is said, "from stillness and purity radiance is born." Because from the second dhyāna onward one is free of vitarka and vicāra, there is no speech; they merely emit light by means of the mind of meditative absorption, and their hierarchical stages are distinguished by the superiority or inferiority of their light. In this heaven, the sign of joy first arises, but the light of wisdom is still inferior, so it is called the Heaven of Lesser Light.