This material occurs in no other Gospel. The destruction of Jerusalem that Jesus predicted here was an important event for Luke. It showed God's judgment on Israel for rejecting His Son and provided evidence that God had turned from working with the Jews primarily and was now working with Gentiles equally. It constitutes an argument for the distinctively new dispensation that resulted from the Jews' rejection of their Messiah. It also gives a reason for the Christian mission on which Jesus later sent His disciples.
19:41 Luke continued to describe Jesus as approaching Jerusalem, His city of destiny. Jesus saw the city in the light of its rejection of His gracious offer of salvation. He foresaw it visited in judgment later since it had rejected His peaceful visit. This is the only place in the Gospels beside John 11:35 where we read that Jesus wept. His compassion is something Luke pointed out frequently. The fate of sinners who reject God's grace broke Jesus' heart. Jeremiah also wept over the fate of Jerusalem (Jer. 8:18-22; 15:5; Lam.; cf. 2 Kings 8:11-12).
19:42 Jesus meant that if the people of Jerusalem had only known then, that day (cf. 4:21; 19:5, 9), what would result in peace for them, they could experience peace. Acceptance of Him and the inauguration of the kingdom would bring peace (i.e., salvation) to the city of peace, Jerusalem. However they did not realize the consequences of their decision. God had withheld that insight from them because they were bent on rejecting Jesus (11:49-51; 13:34).
19:43-44 The enemies in view proved to be the Roman soldiers under Titus who besieged Jerusalem as Jesus described, breached its walls, and finally leveled it in 70 A.D. (cf. 21:20-24). The reason for its destruction was its failure to realize Messiah's visit and His offer of salvation. Consequently His visit would result in judgment.
