仁王般若經疏 3.188

3.188

爾時十六國下，品中大段第三，諸國王聞佛七誡不制四眾。就文為二：初十六國王悲歎驚怖，傷己已往愆，依教不制四眾。第二十八梵天等傷歎云當當爾之時世間空虛是無佛世者，歎正法滅盡，故名無佛世也。

From "At that time, the sixteen [great] kings" onward is the third major section of the chapter: the various kings hear the Buddha's seven admonitions and do not regulate the fourfold assembly. In the text there are two [parts]: first, the sixteen kings grieve, sigh, and are terrified, lamenting their past errors, and following the teachings they do not regulate the fourfold assembly. Second, the eighteen Brahmā kings and others lament and sigh, saying that at that time the world will be empty and desolate, an age without a Buddha; this laments that the correct Dharma will have perished completely, hence it is called "an age without a Buddha."