大般涅槃經集解 60.50

60.50

案僧宗曰：第三，舉三種病人，起慈悲之重。父母以恩養邊重，如來以四中最勝，施此三其福則等。引此為證也。

Sengzong states: Third, adducing the three kinds of sick people evokes the gravity of loving-kindness and compassion. Parents are of heavy [merit] on the side of their kindness in nurturing; the Tathāgata is the most supreme among the four [fields of merit]; giving to these three brings equal merit. This is cited as proof.