Isaiah 1:9 uses the same 'if the Lord had not' logic — God preserves a remnant from total destruction, paralleling the shortening of days for the elect.

Isaiah 65:8 says God spares a cluster for His servants' sake — directly parallel to shortening days for the elect.

Matthew 24:22 is the parallel passage, nearly identical: days shortened for the elect's sake.

Romans 11:5-7 speaks of a remnant chosen by grace — the elect concept directly mirrors the shortening of days for them.

Isaiah 45:4 explicitly says 'for the sake of my chosen' — this same motive is the reason the days are shortened for the elect in Mark.

Ezekiel 14:22 speaks of survivors left after judgment — this parallels God preserving the elect through the tribulation in Mark.

Matthew 19:25 asks 'Who then can be saved?' — Mark 13:20 answers: no one, unless God mercifully shortens the days.

Luke 21:22 describes the same period as 'days of vengeance,' adding a judgment dimension to the shortened days for the elect.

Deuteronomy 28:62 presents being 'few' as a curse for disobedience — contrast with God's merciful shortening of days here to preserve the elect.

1 Peter 4:18 quotes that the righteous are scarcely saved, illustrating the difficulty of salvation apart from God's shortening of days.

Isaiah 6:13 describes a holy seed remaining after judgment, echoing the theme of a preserved remnant for the elect.

Isaiah 65:9 promises the chosen will possess the land, reinforcing God's preservation of a remnant for His people.

Zechariah 13:8 speaks of a third being left alive after judgment, similar to the elect surviving the shortened days.

Zechariah 13:9 refines the remnant as silver and calls them God's people — parallels the elect being saved and tested.

Romans 11:28-32 reveals God's mercy toward the elect — the same divine faithfulness that shortens the tribulation for their sake.

1 Peter 1:2 speaks of the elect being chosen according to God's foreknowledge, reinforcing the divine election mentioned in Mark 13:20.