Therefore speak I to them in parables
Because it was the will and pleasure of his Father to give the knowledge of divine mysteries to some, and not to others; and because even the outward good things they had, being wrongly used or abused by them, would be taken away from them:
and because they seeing, see not:
they saw Christ with their bodily eyes, but not with an eye of faith; they saw the miracles he did, but did not discern, at least did not acknowledge the evidence of them, proving him to be the true Messiah.
And hearing, they hear not, neither do they understand:
they heard externally, but not internally; they heard the sound of Christ's voice, but did not understand his words, even when he spake in the plainest and most intelligible manner; nor were they concerned to know the meaning of them: wherefore he spoke to them in this abstruse and parabolical way, that they might be what they really were, seers and not seers, hearers and not hearers, at least not understanding ones; and that what he said might remain sealed and hidden to them, as the things contained in the sealed book were to the Jews of old; the reason of which was, as a writer of their's F11 says, and which agrees with our Lord's reason and conduct here, (hdyxw lvmb wyhv) , "because they were in parable and riddle".
F11 Abarbinel in Isa. 29. 11.