Charles Ellicott Commentary Luke 19:42

"saying, If thou hadst known in this day, even thou, the things which belong unto peace! but now they are hid from thine eyes." — Luke 19:42 (ASV)

If thou hadst known, even thou.—The emphatic repetition of the pronoun, as in Isaiah 48:15; Isaiah 51:12; Ezekiel 5:8; Ezekiel 6:3; Psalms 76:7, speaks of the strongest possible emotion. The broken form of the sentence, If thou hadst known . . . , with no corresponding clause as to what would then have followed; the at least in this thy day, the day that was still its own, in which it was called to repentance and action, all point to the words as being the utterance of the deepest human sorrow that the Son of Man had known.

The things which belong unto thy peace.—Literally, the things that make for, or tend to, peace. The Greek is the same as that translated conditions of peace in Luke 14:32 (where see Note); in this case, obviously, the “things that make for peace” are repentance, reformation, righteousness.

Now they are hid.—The Greek tense implies, by a distinction hard to express in English, in conjunction with the adverb now, that the concealment of the things that made for the peace of Jerusalem was a thing completed in the past.