In the section referred to exegesis as “heqiu qi benshi” 覈求其本釈 of the last part of the second volume of Tanluan’s 曇鸞 Wangsheng lunzhu 往生論註 (Commentary of Vasubandhu’s discourse on the Pure Land), Tanluan examines the deep roots of sentient beings’ salvation through the Pure Land teaching. The discussion of this section is parallels the section of the supplementary discussion, focusing on the beings to be saved, in the latter part of the first volume. Chikū 知空, an Edo period Honganji-ha scholar, analyzed this section in his Muryōjukyō ronchū yokuge 無量寿経論註翼解. While demonstrating the core teaching of Jōdo Shinshū, his methodology is essentially based on the principles of Buddhism as a whole, with citations from the Tang dynasty scholar Chengguan’s 澄観 commentaries on the Huayan jing 華厳経, as well as passages from Jōdoshū scholars such as Ryōchū 良忠 and Ryōe 了慧.
Chikū’s great achievement is, that, with a straightforward reading of Tanluan’s Wangsheng lunzhu, he shows that Tanluan’s theory of Other-Power can be understood “in consideration of [the state of] a Buddha, or in consideration of [the state of] sentient beings” (yakubutsu 約仏, yakushō 約生), or from the direction of Buddha(s) to sentient beings and sentient beings to Buddha(s) (jūbutsu kōshō 従仏向生, jūshō kōbutsu 従生向仏). Chikū takes a multifaceted approach to Shinran’s 親鸞 “profound doctrine of benefit by the Other and benefit for others,” which is based on Tanluan’s idea that the Other-Power path of Amitābha’s Primal Vow assures the swift realization of Buddhahood, in contrast to the generalized Buddhist notion that the bodhisattva path is a path of gradual realization.