A.T. Robertson Commentary Matthew 24:22

"And except those days had been shortened, no flesh would have been saved: but for the elect`s sake those days shall be shortened." — Matthew 24:22 (ASV)

Had been shortened (εκολοβωθησαν). From κολοβος, lopped, mutilated, as the hands, the feet. It is a second-class condition, determined as unfulfilled. It is a prophetic figure, the future regarded as past.

For the elect's sake (δια τους εκλεκτους). See Mt 22:14 for another use of this phrase by Jesus and also 24:31. The siege was shortened by various historical events like the stopping of the strengthening of the walls by Herod Agrippa by orders from the Emperor, the sudden arrival of Titus, the neglect of the Jews to prepare for a long siege. "Titus himself confessed that God was against the Jews, since otherwise neither his armies nor his engines would have availed against their defences" (Vincent).