Charles Ellicott Commentary Matthew 23:39

"For I say unto you, Ye shall not see me henceforth, till ye shall say, Blessed [is] he that cometh in the name of the Lord." — Matthew 23:39 (ASV)

Till you say — This phrase obviously refers to the words from Psalm 118:26, which the crowd had uttered just a few days before during His solemn entry into Jerusalem.

They would not look on Him again until those words are uttered once more—not in a momentary burst of excitement or with false Hosannas, but in spirit and in truth. There can be little doubt that our Lord is pointing to His second coming and the welcome that will then be given to Him by all the true Israel of God. For that generation, and for the visible nation of Israel as such, the abandonment was final.