How do we know that God's mercy is discriminative?

The notion of God's discriminative mercy is clearly illustrated in the narrative of the Egyptian plagues. As God sends judgment upon Egypt, He makes a distinction between the Egyptians and the Israelites, as stated in Exodus 8:22-23, where God says, 'I will put a difference between my people and thy people.' This distinction emphasizes that God's favor and mercy are not based on any inherent merit in the individuals but are solely a reflection of His sovereign choice. It reminds us that mercy and grace are gifts given at the discretion of God, who is free to choose according to His will. Understanding this doctrine deepens our appreciation of grace, illustrating that none of us are deserving, and God's choice to show mercy is rooted deeply in His character and purposes.