大方廣佛華嚴經疏 49.38

49.38

Third is the simile of the great ocean secretly benefiting, which illustrates the Buddha's wisdom of benefiting beings with an equal essence; this doubly explains the prior meanings of 'support' and 'producing'. That is to say, because it is of the same essence as the minds of sentient beings, the principle is called 'secretly flowing'. When, by boring and digging into one's own mind, one attains wisdom, that is seeing the wisdom of the other Buddha; this is called being produced based upon it. Furthermore, because the essence is identical, the external Buddha's empowerment augments one's power of mindfulness; this too is an 'inflowing'.