觀無量壽佛經疏 3.103

3.103

答曰：「欲顯諸佛三身同證，悲智果圓等齊無二。端身一坐影現無方，意赴有緣時臨法界。言法界者，有三義：一者心遍故解法界。二者身遍故解法界。三者無障礙故解法界。正由心到故身亦隨到，身隨於心，故言是法界身也。言法界者，是所化之境，即眾生界也。言身者，是能化之身，即諸佛身也。言入眾生心想中者，乃由眾生起念願見諸佛，佛即以無礙智知，即能入彼想心中現。但諸行者，若想念中、若夢定中見佛者，即成斯義也。」

Answer: "It is to show that all Buddhas equally realize the three bodies, their fruit of compassion and wisdom is complete, even, and non-dual. Sitting upright in one body, their reflections manifest boundlessly; their intention reaches those with karmic affinity, approaching the dharmadhātu in an instant. The term 'dharmadhātu' has three meanings: first, because the mind is all-pervading, it is understood as dharmadhātu; second, because the body is all-pervading, it is understood as dharmadhātu; third, because it is unimpeded, it is understood as dharmadhātu. Precisely because the mind arrives, the body also follows and arrives; the body follows the mind, and therefore it is called the 'dharmadhātu body.' As for 'dharmadhātu,' it is the realm to be transformed, namely the realm of sentient beings. As for 'body,' it is the body capable of transforming, namely the body of all Buddhas. As for 'entering the mental visualization of sentient beings,' it is because when sentient beings give rise to thoughts wishing to see the Buddhas, the Buddhas instantly know with unimpeded wisdom and can enter and manifest within that visualizing mind. As long as practitioners see the Buddha whether in mindfulness, in dreams, or in samādhi, this meaning is accomplished."