Comm. NT: 36. “Comprehending” (sammasana) is a technical term that will become clear in Chapter XX. In short, it is inference that generalizes the “three characteristics” from one’s own directly-known experience to all possible formed experience at all times (see S II 107). Commenting on “He comprehended that same illness” (§138), Vism-mhṭ says:
Paṭhamasīlapañcakavaṇṇanā
He exercised insight by discerning the feeling in the illness under the heading of the feeling [aggregate] and the remaining material dhammas as materiality