Commentary on the Sūtra of the Collection of the Father and Son (105)

Some people with cultivation know, even while dreaming, that the dream is unreal. When karmic conditions manifest in the dream and they are about to commit an evil deed, they immediately know in their mind that this must not be done, and the mind does not drift along with the object. For such a person, the mind consciousness is awakened, and the manas has also awakened to a certain degree, being able to take charge and refrain from committing evil deeds. Then, after death, that person will likewise be able to take charge and refrain from committing evil deeds. Those who commit evil deeds in dreams still lack strength in the cultivation of their mind consciousnesses. Therefore, dreams can test whether we have cultivation, and to what degree we have cultivated—whether the manas has been infused, whether it has strength, and whether we have any assurance regarding birth and death.