“such tribulation.” This is the time of “great tribulation” Jesus spoke of in Matthew 24:21. Jesus would have learned a lot about the Tribulation period from the Old Testament. This great tribulation is the subject of much of the book of Revelation, with its seven seals, seven trumpets, seven thunders, and seven bowls of judgment.
[For more on the prophecies of the Great Tribulation, see commentary on Isa. 13:9.]