瑜伽論記 17.450

17.450

答：三定自地於生死中有最勝樂，恐退沒故，立正智而防護之，四定但有他地留難，無自地難，是故不立正智為支，又正智如明，捨受如無明，明無明相違，故不立支。

Answer: In the third dhyāna's own stage, there is the supreme pleasure within saṃsāra; fearing regression and falling, correct knowledge is established to guard against it. In the fourth dhyāna, there are only obstacles from other stages and no difficulties from its own stage; therefore, correct knowledge is not established as a limb. Furthermore, correct knowledge is like light, and neutral feeling is like darkness; light and darkness are mutually opposed, so it is not established as a limb.