四明尊者教行錄 2.23

2.23

Question: That the dharmadhātu entering the mind and 'this mind is the Buddha' constitute the substance of the wondrous contemplation is not doubted by those who understand. However, in the sūtra text, this stands at the head of the contemplation of the image; since the subsequent contemplations have this standard substance, they may immediately possess the three. Prior to this, the Buddha had not yet revealed it across the preceding gates; on what basis should one cultivate the threefold contemplation in each of them?