Saṃyuktāgama Sūtra (359)

Original text: 如是我闻。一时。佛住舍卫国祇树给孤独园。尔时。世尊告诸比丘。若思量。若妄想生。彼使攀缘识住。有攀缘识住故。有未来世生老病死忧悲恼苦。如是纯大苦聚集。若不思量。不妄想。无使攀缘识住。无攀缘识住故。于未来世生老病死忧悲恼苦灭。如是纯大苦聚灭。佛说此经已。诸比丘闻佛所说。欢喜奉行。  

Explanation: The World-Honored One told the bhikṣus: If a person's mind gives rise to deliberation (manasikāra) and false imaginings, this will cause the six consciousnesses that grasp at the six sense objects to arise and abide upon the six sense objects; because the six consciousnesses abide upon the six sense objects, there will be future-life birth, aging, death, sorrow, grief, suffering, and distress (śoka-parideva-duḥkha-daurmanasyopāyāsa) — the accumulation of the great mass of suffering. If a person no longer deliberates and has no false imaginings, then the six consciousnesses that grasp at the six sense objects will not arise and abide upon the six sense objects; because there are no six consciousnesses grasping at the six sense objects abiding there, the future-life birth, aging, death, sorrow, grief, suffering, and distress — the great mass of suffering — will cease and no longer appear. 

The deliberation and false imaginings spoken of here both refer to the deliberative nature and imagining nature of the manas. When the manas deliberates upon and imagines the various dharmas, the six consciousnesses will arise to satisfy the manas's imaginings and actualize them; thus the six consciousnesses will abide upon the imagined realms, continually engaging in bodily, verbal, and mental actions, and karmic seeds will be retained, so that in a future life a five-aggregate (pañca-skandha) body will come to undergo birth, aging, death, sorrow, grief, suffering, and distress. If the manas no longer deliberates upon the various dharmas and has no false imaginings, the six consciousnesses will not arise, bodily, verbal, and mental actions will not occur, no karmic seeds will be retained, and there will be no future birth, aging, death, sorrow, grief, suffering, and distress.