This term, as noun, occurs probably for the first time in Pts.M. I. 53, although as a verb it is found already in the old texts. The same holds good with its synonym vavattha^na.
”comprehension”, exploring, ”determining” (vavattha^na, q.v.) is a name for the determining of all phenomena of existence as impermanent, miserable and impersonal (anicca, dukkha, anatta^), etc., which is the beginning of insight (s. Pts.M. I, p. 53; Vis.M. XX); also called kala^pa-s. (q.v.), ”comprehension by groups (of existence - khandha).” (App.).