俱舍論頌疏論本 7.49

7.49

無覆如色辨者，無色無覆如色界辨，從三心生，能生六心。從三心生者，謂自界三。能生六心者，謂自界三及色界染，兼欲界二不善有覆。

"Unimpeded is explained like [that of] the form [realm]": the unimpeded of the formless is explained like [that of] the form realm: it arises from three minds and can give rise to six minds. Arising from three minds means the three of its own realm. Being able to give rise to six minds means the three of its own realm, the defiled of the form realm, and in addition the two of the desire realm, the unwholesome and the impeded.