What does the Bible say about God's sovereignty in mercy?

The concept of God's sovereignty in showing mercy is a central theme in Scripture. Romans 9:15 says, '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.' This indicates that God's decisions are based on His will and purpose rather than human merit or effort. In the story of Jacob blessing Ephraim and Manasseh, we see that God chose the younger, Ephraim, to receive the primacy of the blessing despite Manasseh being the firstborn. This is a clear depiction of God's sovereign choice that does not follow human expectations.