大乘起信論義記 3.320

3.320

釋中言直心者，謂向理之心，無別岐徑，故云正念真如即二行之本也。言深心者，備具萬德，歸向心源，故云樂集等也。上來二種，自利行本也。言大悲心者，廣拔物苦，令得菩提，故云欲拔等也，即利他行本。妙行雖廣，三行統收，故上云略說三也。以此即是三聚戒故、三德三身皆由此故，亦即是彼三迴向故，謂初迴向實際，次向菩提，後向眾生。皆應相配釋之。

In the explanation, “straightforward mind” refers to the mind turning toward the principle without any diverging path; hence “correctly being mindful of tathatā” is the root of the two practices. “Profound mind” refers to being fully equipped with the myriad virtues and returning to the source of the mind; hence it says “delighting in accumulating,” and so forth. The two preceding kinds are the root of practices for one's own benefit. “Mind of great compassion” refers to broadly pulling out the suffering of creatures and causing them to attain bodhi; hence it says “wishing to pull out,” and so forth, which is the root of practices that benefit others. Although wondrous practices are vast, the three practices comprehensively subsume them; hence it was said above that three are briefly stated. Because these are the three clusters of precepts, because the three virtues and three bodies all stem from this, and also because these are the three pariṇāmanās—namely, the first is dedicated to ultimate reality, the next is dedicated to bodhi, and the last is dedicated to sentient beings. All of them should be explained in correspondence with this.