9. we also--on our part.
      heard it-- (Col 1:4).
      pray--Here he states what in particular he prays for; as in Col 1:3 he stated generally the fact of his praying for them.
      to desire--"to make request."
      might be filled--rather, "may be filled"; a verb, often found in this Epistle (Col 4:12, 17).
      knowledge--Greek, "full and accurate knowledge." Akin to the Greek for "knew" (see on Col 1:6).
      of his will--as to how ye ought to walk (Eph 5:17); as well as chiefly that "mystery of His will, according to His good pleasure which He purposed in Himself; that in the fulness of times He might gather together in one all things in Christ" (Eph 1:9, 10); God's "will," whereby He eternally purposed to reconcile to Himself, and save men by Christ, not by angels, as the false teachers in some degree taught (Col 2:18) [ESTIUS]. There seems to have been a want of knowledge among the Colossians; notwithstanding their general excellencies; hence he so often dwells on this subject (Col 1:28; Col 2:2, 3; 3:10, 13; 4:5, 6). On the contrary he less extols wisdom to the Corinthians, who were puffed up with the conceit of knowledge.
      wisdom--often mentioned in this Epistle, as opposed to the (false) "philosophy" and "show of wisdom" (Col 2:8, 23; compare Eph 1:8).
      understanding--sagacity to discern what on each occasion is suited to the place and the time; its seat is "the understanding" or intellect; wisdom is more general and has its seat in the whole compass of the faculties of the soul [BENGEL]. "Wouldst thou know that the matters in the word of Christ are real things? Then never read them for mere knowledge sake" [Quoted by GAUSSEN.] Knowledge is desirable only when seasoned by "spiritual understanding."

JFB.