仁王護國般若波羅蜜多經疏 3.532

3.532

解曰：王若行時，常以此經導引其前。傳聞西方有佛法處，諸國國王皆以般若為鎮國寶，王若出行以經先導，即得國界無災難矣。從此第四住處供養。

Explanation: Whenever the king travels, he should always have this sūtra lead the way in front. It is traditionally reported that in the Western Regions, where the Buddhadharma exists, the kings of all states regard prajñā as the treasure that protects the realm; if the king goes forth, he takes the sūtra as the vanguard, and thus his realm is free of calamities. Hereafter is the fourth part: making offerings at one's dwelling place.