Yogācārabhūmi Śāstra, Volume 34 (65)

Original text: 又于涅槃深心愿乐。速能趣入。心无退转。离诸怖畏。摄受增上意乐适悦。如是行者。于诸圣谛。下忍所摄。能缘所缘平等。平等智生。是名为暖。中忍所摄。能缘所缘平等。平等智生。是名为顶。上忍所摄。能缘所缘平等。平等智生。名谛顺忍。

Explanation: Furthermore, one deeply delights in nirvāṇa with a profound mind, can swiftly enter into it, the mind does not regress, one departs from all fears, and one embraces intensified aspiration (adhimātra-adhimukti) with comfort and joy. Such a practitioner, in the cultivation of the four noble truths, is encompassed by the lower grade of forbearance. When the mind that perceives and the dharma that is perceived are equal, and the wisdom of equality arises, this is called the stage of heat (ūṣma-gata). It is encompassed by the middle grade of forbearance. When the mind that perceives and the dharma that is perceived are equal, and the wisdom of equality arises, this is called the peak (mūrdhan). It is encompassed by the upper grade of forbearance. When the mind that perceives and the dharma that is perceived are equal, and the wisdom of equality arises, this is called the forbearance accordant with the truths (satyānulomikī kṣānti).

Here, the forbearance regarding nirvāṇa is divided into three grades—upper, middle, and lower. The lower grade of forbearance corresponds to the stage of heat among the four aids to penetration (nirvedha-bhāgīya); the middle grade of forbearance corresponds to the stage of peak among the four aids to penetration; the upper forbearance, also called the forbearance accordant with the truths, corresponds to the stage of forbearance (kṣānti) among the four aids to penetration. A practitioner at the stage of heat can already incline the mind toward nirvāṇa, and in cultivating the dharma of nirvāṇa, the mind no longer regresses, because intensified aspiration toward the dharma of nirvāṇa has arisen, fears have been departed from, and there is the beneficial experience of merit. Then in all subsequent cultivation there will be no regression, and even after eradicating the view of self (satkāya-dṛṣṭi-prahāṇa) and attaining the first fruit, one will regress even less from the path to nirvāṇa. The beneficial experience of merit at the stage of the four aids to penetration differs greatly from that of the first fruit; the first fruit and the second fruit, and even the second fruit compared with the third and fourth fruits, all differ greatly in their beneficial experience of merit. Therefore, do not misunderstand the beneficial experience of merit; do not mistake the beneficial experience of merit of the four aids to penetration for that of the first or second fruit, thereby committing the grave false speech of claiming realization that has not been realized.