In the Ōjōyōshū 往生要集, Genshin 源信 praises Amitābha Buddha as the “Honored One Perfectly Integrated with Complete Virtues” (ennyū mantokuson 円融万徳尊) which Shinran 親鸞 cites in the “Gyōmonrui” 行文類 in the Kyōgyōshinshō 教行信証. By examining Genshin’s usage of the word ennyū (perfectly integrated), we see that he straightforwardly applies the Tendai understanding of Buddha bodies as “three bodies in one” (sanshin sokuitsu 三身即一) or “many buddhas in the same body” (shobutsu dōtai 諸仏同体) to Amitābha Buddha in accordance with Tendai views on santai ennyū 三諦円融, sanzen engu 三千円具 (the true aspect of reality which is perfect integration of the “Triple Truth” and three thousand existences in the entire universe) based on the Tendai theory of the “Three Truths.” Though using the same word, Shinran did not rely on this latter Tendai theory. Instead, he adopted a twofold truth theory to understand the meaning of ennyū based on Tanluan’s 曇鸞 theory of two kinds of dharma-bodies discussed in his Wangshenglun zhu 往生論註 (Commentary on the discourse on birth in the Pure Land). Shinran further developed his soteriological understanding of the concept of ennyū as the state of mutual integration of the twofold truth with the word jinen 自然 (the ultimate reality as seen in “things-as-they-are”) by saying “Amitābha Buddha fulfills the purpose of making us know the significance of jinen.” Thus, while Genshin uses the word ennyū to express the meaning that Amitābha Buddha fulfills all virtues in his single body, Shinran uses the word to express the dynamic working of Amitābha’s Name actively and naturally saving all sentient beings.