大般涅槃經義記 5.331

5.331

自下第二辯前所修非大所以。迦葉先問「世尊何緣得如是慈，猶不名大」，下佛為釋，「以難成故不名大者」略釋非大，「何以故」下廣釋非大，於中初法，「如豌豆」下四喻顯之。

From here below, the second [part] explains the reason why what was previously cultivated is not great. Kāśyapa first asks: "World-Honoured One, for what reason is attaining such benevolence still not called great?" Below, the Buddha explains it for him: "Because it is difficult to accomplish, it is not called great" briefly explains why it is not great; from "why is that" onward extensively explains why it is not great, in which there is first the dharma, and from "like a pea" onward, four analogies demonstrate it.