無量壽經連義述文贊 3.43

3.43

經曰「壽命甚難得」至「若聞精勤求」者，述云：第三、勸令求願。有三：此初、勸聞勤求也。既離三難，不容空過故。壽是道依、佛為勝緣、信即行本，故偏說之。

On the sūtra's words from "Lifespan is extremely difficult to obtain" to "If one hears it, one should diligently seek it," the Commentary states: Third, exhorting them to make vows. There are three parts: this first exhorts them to hear it and diligently seek it. Having escaped the three difficulties, one should not let it pass in vain. Lifespan is the support for the path, the Buddha is the supreme condition, and faith is the root of practice; hence these are specifically spoken of.