Jonah 1:2 Arise, go to Nineveh, that great city, and cry against it;
for their wickedness is come up before me.
Jonah 3:10 And God saw their works, that
they turned from their evil way; and
God repented of the evil, that he had said that he would do unto them;
and he did [it] not.
The Ninevites deserved God's wrath, but showed them mercy.
2 Chron 12:12 And when he humbled himself,
the wrath of the LORD turned from him, that he would not destroy [him] altogether: and also in Judah things went well.
Cain was also shown mercy after killing Abel.
For he saith to Moses, I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion.