佛說盂蘭盆經疏 2.92

2.92

"If a disciple of the Buddha cultivates filial obedience": this shows by contrast that those who are not disciples of the Buddha and those who are unfilial may leave off setting out the offering of the basin at will. "In thought after thought always remember": without end or beginning. Nurturing is the matter; loving care is the mind. Therefore, one previously undertook the practice and generated the mental vow in order to repay them. The rest of the text is intelligible. The Tripiṭaka Master says: "Since parents' knot of love does not leave their thoughts in thought after thought, the filial child's repayment of kindness must not break off offerings year after year."