大乘義章 19.19

19.19

次約諸佛以辨三身。如彼經說「其化身者與佛同事，同諸如來變化之事。其應身者與佛同意，同諸佛如來顯揚佛法化益之意。其真身者與佛同體，一切諸佛以如如法如如之智而為體故（此三門竟）。」

Next, the three bodies are distinguished with reference to the Buddhas. As that sūtra says: 'The transformation body shares deeds with the Buddhas, sharing the activities of transformation of all Tathāgatas. The response body shares intention with the Buddhas, sharing the intention of all Buddha Tathāgatas to proclaim the Buddha-dharma and transform and benefit [beings]. The true body shares substance with the Buddhas, because all Buddhas take the dharma of thusness and the wisdom of thusness as their substance.' (This concludes the three sections.)