佛說盂蘭盆經疏 2.89

2.89

所修必假行門，所獲必繇心願。願者心之樂欲，欲得存歿咸安。存者保壽於人間，常無病惱；歿者遷神於天上，永絕冥塗。行願相資，無所不利。

What is cultivated must rely on the gateway of practice; what is obtained must arise from the aspiration of the mind. A vow is the mind's wish and desire, desiring that the living and the departed both find peace. The living preserve their longevity in the human realm, always free from illness and distress; the departed transfer their spirits to the heavens, forever severed from the dark paths. Practice and vows assist each other, and there is nothing in which they are not beneficial.