大般涅槃經集解 3.20

3.20

案僧宗曰：歎呪功能，復明己自為護，以勸受持也。慧朗曰：此第三請佛受供印呪。佛不受供，而印其呪也。

Sengzong states: "Praising the function of the dhāraṇī-spell, he further explains that he himself will protect them, so as to encourage receiving and upholding it." Huilang states: "Third, this is the request for the Buddha to accept the offerings and seal the dhāraṇī-spell. The Buddha did not accept the offerings, but sealed his dhāraṇī-spell."