觀無量壽佛經疏 4.32

4.32

八、從具此功德已下，正明修行時節延促。上盡一形，下至一日、一時、一念等，或從一念十念至一時一日一形。大意者，一發心已後誓畢此生，無有退轉，唯以淨土為期。又言具此功德者，或一人具上二，或一人具下二，或一人三種盡具。或有人三種無分者，名作著人皮畜生，非名人也。又不問具三不具三，迴盡得往生。應知。

Eighth, from 'endowed with these merits' downwards, directly clarifies the duration—whether extended or brief—of cultivating practice: from an entire lifetime at the highest, down to one day, one period, or one thought-moment; or from one thought-moment or ten thought-moments, to one period, one day, or an entire lifetime. The general meaning is that, once the aspiration has been generated, one vows to complete this lifetime without turning back, setting one's goal on the Pure Land alone. Furthermore, regarding 'endowed with these merits,' either one person is endowed with the upper two, or one person is endowed with the lower two, or one person is completely endowed with all three kinds. If there is a person who has no share in any of the three kinds, they are called 'a beast wearing human skin,' not a human being. Moreover, regardless of whether one is endowed with the three or not endowed with the three, by dedicating them all one attains rebirth. One should know this.