New Defender's Study Bible Notes
19:42 this thy day. “This thy day” was the day when the Scriptures had said that Messiah would present Himself to Judah and Jerusalem as their promised King. The time of His coming had been foretold in Daniel 9:25, and the manner of His coming in Zechariah 9:9. A believing remnant had recognized Him, but the leaders and most of the people did not. On the very day when they should have crowned Him King, they set about to destroy Him (Luke 19:47).
19:44 even with the ground. This terrible prophecy was fulfilled in A.D. 70, when the Roman army under Titus destroyed the temple completely. The destruction of the city and dispersion of its people was completed in A.D. 135.
19:44 knewest not the time. If the Jewish scribes had really searched and studied the Scriptures (especially Daniel 9:24-25), they could have known “the time of thy visitation.”