佛說觀佛三昧海經 10.25

10.25

The Buddha said to Ānanda: “After the Buddha's parinirvāṇa, if disciples of the Buddha wish to contemplate the Buddhas of the ten directions, while in the buddhānusmṛti-samādhi they will only know the coarse marks, but they will naturally come to know the immeasurable wondrous marks. Contemplating in this way is called correct contemplation; if one contemplates otherwise, it is called false contemplation. One who attains this contemplation sees Buddhas beyond number and limit. One who enters this concentration is said to see the rūpakāyas of all Buddhas, and also gradually enters the three gates of emptiness. Roaming in this emptiness, through the power of the Buddhas one's mind does not cling to emptiness, and in a future age one will attain anuttarā-samyak-saṃbodhi and achieve non-retrogression. This is called not forgetting the bodhicitta and correctly according with the Buddha path.”