As stated:

He has full recollection of the past states of these sentient beings. The Tathāgata knows past causes, and what past causes led to someone becoming a certain sentient being, and with this knowledge he teaches the Dharma accordingly. The Tathāgata knows the past mind states of all sentient beings. The Tathāgata knows which mental objects arose after which, the objects which made things arise, and the objects whose absence made something cease. Even if one were to try for as many aeons as there are grains of sand in the river Ganges. it would be difficult to fully express the workings of the mind of a single sentient being, one state of mind after another – that after it was in such and such a way, the mind was like this, and after that it was like this. But the Tathāgata knows the continuity of mind, each thought following the other, of all sentient beings. And if it could be conceived of, his wisdom would not reach its limit even if this was demonstrated until the very end of existence. The Tathāgata’s knowledge of past states is inconceivable and incomparable; and being immeasurable, to show its full extent is no easy matter. The Tathāgata, the bull-like Buddha, reminds sentient beings, ‘Take heed. Remember that these are the roots of virtue that cause sentient beings to be born as buddhas, as hearers and as solitary buddhas.’ It is by the power of the Buddha that they are reminded of this. The Tathāgata will consider which roots of virtue they are drawn to, through which vehicle they can be liberated and reach the point of no return, and teaches the Dharma accordingly. This is the eight tathāgata-activity of the Tathāgata.¹