釋淨土群疑論 2.41

2.41

Explanation: All karmas are indeterminate; some turn the heavy into the light, and some shorten what was long, fully as explained in the sūtras and impossible to recount in full. Although the practitioner originally received the precepts vowing to be born in heaven, later they encountered superior conditions and turned toward rebirth in the Pure Land. Although the practice was inferior and weak, because the later vow is strong, it assists the prior grade of precepts so that they become increasingly superior; matching the Buddha's vow, their lifespan is prolonged to an asaṃkhyeya of kalpas. It is like relinquishing practices of merit to perform practices of life: some people, though wealthy, are sickly and short-lived; by giving away their goods and entering samādhi, or relinquishing their robes and bowl to make karma that extends the faculty of life, their lifespan is increased and lengthened even further. The Buddha's power, the Dharma's power, the power of vows, and the power of karma are inconceivable, beyond the calculation of ordinary beings.