The Yogācārabhūmi-śāstra, Volume 34 (56)

Furthermore, the mental application of discerning characteristics as described above should be understood as still being mixed with learning and reflection. If the practitioner, through repeatedly and correctly contemplating the truths in this manner, gains mental determination regarding the validating principles of the Four Noble Truths via the sixteen aspects, and further, regarding the all aspects (yāvadbhāvikatā) and the suchness (yathāvadbhāvikatā) of these truths, surpasses mental application mixed with learning and reflection, and instead generates exclusively the conviction born of cultivation, this is then called the mental application of conviction (adhimokṣa-manaskāra). Such mental application is directed solely towards the object of the truths and abides constantly in meditative concentration. By cultivating and diligently practicing this mental application of conviction, one attains the wisdom of boundlessness (anantajñāna) within the objects of the truths of suffering and its origin.

Explanation: The mental application of discerning characteristics mentioned above still belongs to wisdom mixed with learning and reflection. If the practitioner correctly contemplates the Four Noble Truths uninterruptedly in this way, mental determination regarding the validating principles of the Four Noble Truths is attained through the sixteen aspects. Furthermore, regarding the all aspects and the suchness of the Four Noble Truths, having surpassed mental application mixed with learning and reflection, one generates exclusively the conviction born of cultivation, which is named the mental application of conviction. Such mental application is directed solely towards the true state (real object) and abides constantly in meditative concentration. Due to cultivating and diligently practicing this mental application of conviction, one then attains the wisdom of boundlessness within the two objects of the truths of suffering and its origin.

The mental application of discerning characteristics prior to attaining mental determination regarding the Four Noble Truths is mixed with learning and reflection; it is not pure correct contemplation nor is it uninterrupted observation. Only if one can contemplate correctly without interruption can mental determination regarding the Four Noble Truths be attained. After mental determination is attained, conviction (adhimokṣa) can arise; after conviction arises, realization (abhisamaya) can occur. The "all aspects" of the Four Noble Truths refers to the scope covered by the Four Noble Truths; "suchness" refers to all natures that accord with the principle of the Four Noble Truths. If the observation is uninterrupted correct contemplation, one can surpass the stage mixed with learning and reflection. At this point, one can generate conviction (adhimokṣa) in the Four Noble Truths, called the mental application of conviction. If one can maintain meditative concentration constantly, without losing it, with the mind dwelling exclusively on the Four Noble Truths without engaging other objects, such mental application and observation can lead to the attainment of the wisdom of boundlessness.