What does the Bible say about God's mercy in the book of Jonah?

In Jonah 4, God demonstrates His mercy by sparing Nineveh after they repent at Jonah's preaching. Despite Jonah's anger at God's forgiveness towards this Gentile city, it showcases God's eternal purpose to save even the most undeserving. As seen in Romans 9:20-24, God has the sovereign right to show mercy to whom He chooses, emphasizing His grace towards sinners like us. This account challenges believers to recognize that our own salvation is rooted in the same mercy we may be reluctant to extend to others.