金剛經纂要刊定記 2.9

2.9

As for "repaying the cause": "repay" means repaying, and "cause" means the causal stage. Because when the Buddha first generated the mind at the causal stage, he sought unexcelled complete bodhi and thereupon initiated the four great vows: "Afflictions are boundless, I vow to cut them off; Dharma gates are boundless, I vow to study them; sentient beings are boundless, I vow to deliver them; the Buddha Way is unexcelled, I vow to accomplish it." Among these four, three vows were all completed and only one was not yet fulfilled: the vow to deliver sentient beings, while sentient beings are still clearly present. Now, although he has realized the fruition, he does not abandon the causal approach; he manifests a body to expound the Dharma to rescue the multitude of beings so as to repay his former vow, hence it is called "repaying the cause." Thus the Lotus Sūtra says: "I originally made a vow, wishing to make all beings equal to me without difference. As I formerly vowed, it is now fulfilled: transforming all sentient beings and causing them all to enter the Buddha Way."