注維摩詰經 7.160

7.160

什曰：言四禪，取其似床座能離三患也，一離毒螫、二離垢塵、三離濕冷。四禪亦離三患也，離瞋恚毒、貪欲塵、睡眠冷。離此三患，安隱快樂也。肇曰：世人為毒螫下濕，所以伐木為床。菩薩為下界毒惡，故以四禪為床。生曰：四以擬四方也。禪以安樂為理，床之象者也。

[Kumāra]jīva says: Speaking of the four dhyānas takes their resemblance to a couch and seat in being able to leave behind three afflictions: first, leaving behind poisonous stings; second, leaving behind filth and dust; third, leaving behind dampness and cold. The four dhyānas also leave behind three afflictions: leaving behind the poison of anger, the dust of greedy desire, and the cold of torpor and sleep. Leaving behind these three afflictions brings peace and joy.
[Seng]zhao says: Worldly people cut wood to make couches on account of poisonous stings and low dampness. The bodhisattva takes the four dhyānas as a couch on account of the poisonous evils of the lower realm.
[Dao]sheng says: 'Four' corresponds to the four directions. Dhyāna takes peace and joy as its principle, which is the image of a couch.