And they understood {h} none of these things: and this saying was hid from them, neither knew they the things which were spoken.

(h) By this we see how ignorant the disciples were.

People's New Testament

18:31-34 Behold, we go up to Jerusalem. See notes on Mt 20:17-19 Mr 10:32-34. Luke adds:

All the things that are written by the prophets, etc. For some things written by the prophets, see Ps 16:10 22:7-8 49:15:00 Isa 53:1-9 Da 9:26.

Wesley's Notes

18:34 They understood none of these things - The literal meaning they could not but understand. But as they could not reconcile this to their preconceived opinion of the Messiah, they were utterly at a loss in what parabolical or figurative sense to take what he said concerning his sufferings; having their thoughts still taken up with the temporal kingdom.

Jamieson-Fausset-Brown Bible Commentary

34. understood none, &c.-The Evangelist seems unable to say strongly enough how entirely hidden from them at that time was the sense of these exceeding plain statements: no doubt to add weight to their subsequent testimony, which from this very circumstance was prodigious, and with all the simple-hearted irresistible.

Matthew Henry's Concise Commentary

18:31-34 The Spirit of Christ, in the Old Testament prophets, testified beforehand his sufferings, and the glory that should follow, 1Pe 1:11. The disciples' prejudices were so strong, that they would not understand these things literally. They were so intent upon the prophecies which spake of Christ's glory, that they overlooked those which spake of his sufferings. People run into mistakes, because they read their Bibles by halves, and are only for the smooth things. We are as backward to learn the proper lessons from the sufferings, crucifixion, and resurrection of Christ, as the disciples were to what he told them as to those events; and for the same reason; self-love, and a desire of worldly objects, close our understandings.