2 You should not therefore hold fast things earthly, although God does bestow them....See ye how that in fearing to lose things earthly, the Jews slew the King of Heaven. And what was done to them? They lost even those very things earthly: and in the place where they slew Christ, there they were slain: and when, being unwilling to lose the land, they slew the Giver of life, that same land being slain they lost; and at that very time when they slew Him, in order that by that very time they might be admonished of the reason wherefore they suffered these things.
For when the city of the Jews was overthrown, they were celebrating the Passover, and with many thousands of men the whole nation itself had met together for the celebration of that festival. In that place God (through evil men indeed, but yet Himself good; through unjust men, but Himself just and justly) did so take vengeance upon them, that there were slain many thousands of men, and the city itself was overthrown. Of this thing in this Psalm “the understanding of Asaph” does complain, and in the very plaint the understanding as it were does distinguish things earthly from things heavenly, does distinguish the Old Testament from the New Testament: in order that you may see through what things you are passing, what you should look for, what to forsake, to what to cleave.
Thus then he begins.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)