Genesis 18:26
And the Lord said, If I find in Sodom fifty righteous within the city, then I will spare all the place for their sakes.
Cross-reference
Genesis 18:28 is the direct continuation of the negotiation, with Abraham now specifying the number of righteous needed.
In Isaiah 10:22, only a remnant of Israel returns despite massive numbers — same principle: judgment falls, but God preserves a faithful few.
In Isaiah 65:8, God uses the same principle: as a cluster of grapes is not destroyed because a blessing is found in it, so He will not destroy all for the sake of the righteous.
Jeremiah 5:1 presents the same divine test: to spare Jerusalem if even one just person can be found in it.
Ezekiel 22:30 shows the tragic inverse: God sought a person to stand in the gap and found none, leading to judgment.
In Matthew 24:22, the same mercy logic applies: those days are shortened for the sake of the elect.
Isaiah 1:9 states that a remnant would have been left, echoing the idea that God spares a city for the sake of a few.
In Isaiah 6:13, a 'holy seed' stump remains when judgment falls — the same remnant logic as sparing Sodom for the righteous found within.