Commentary Par I 100-102
We have been made aware of the wonder of those in beatitude at the obtuseness of mortals at least since we first observed the angel finding the plight of Dante at the Gates of Dis of absolutely no interest ([Inf IX 100-103]).  Introduced to this canticle at [Par I 37] and [Par I 116], the word mortale will recur on numerous occasions, and, in this sense (human, and thus intellectually flawed), at least another ten times in Paradiso.  See [Par II 53]; [Par IV 68]; [Par V 64]; [Par XI 1]; [Par XIX 99]; [Par XX 133]; [Par XXVIII 137]; [Par XXIX 132]; [Par XXXIII 32]; [Par XXXIII 68].