大般涅槃經義記 8.141

8.141

「無明覆」下答第四問，明諸眾生不見所由。「無明覆故，令生不見」，別明凡夫不見所由，「聲聞」已下別明二乘不見所由。於中，初明聲聞、緣覺但見空等，不見不空乃至於我，次明不得第一義空，後明不能行於中道。

From "covered by ignorance" onward, it answers the fourth question, explaining the reasons why sentient beings do not see it. "Because they are covered by ignorance, sentient beings are caused not to see [it]" specifically explains the reason ordinary beings do not see it. From "śrāvakas" onward, it specifically explains the reason the two vehicles do not see it. Therein, it first explains that śrāvakas and pratyekabuddhas only see emptiness and so forth, failing to see non-emptiness and likewise the self; next it explains that they do not attain ultimate emptiness; finally it explains that they cannot practice the middle way.