瑜伽論記 8.105

8.105

基法師云：初禪天名梵者梵是淨義，初離欲故故得淨名，第二禪名光者，初離尋伺故得光名，第三禪得淨名者，以得勝樂故，勝樂名淨也，第四禪凡聖共居三天，初無雲得名，餘隨福增為名，五耶含天名云云：解無色界中，云隨行天眾同分中者，無色界天無別受報處，隨行三品即受此報，故言隨行天。

Dharma Master Ji says: The heaven of the first dhyāna is named 'Brahma' because 'Brahma' means purity; having first departed from desire, it receives the name 'pure'. The second dhyāna is named 'radiance'; having first departed from investigation and reflection, it receives the name 'radiance'. The third dhyāna receives the name 'pure'; because it attains supreme bliss, and supreme bliss is called 'pure'. The three heavens of the fourth dhyāna where ordinary beings and noble ones dwell together: the first is named from being cloudless, while the rest are named after the increase of merit. The names of the five Anāgāmin heavens are as stated. Explaining the formless realm, regarding 'within the common lot of sentient beings of the heavens corresponding to practice': the heavens of the formless realm have no separate places for experiencing retribution; according to the three grades of practice, they immediately receive this retribution; hence they are called 'heavens corresponding to practice'.