First born sons belong to God in a special way. In Numbers 3, we read how Hebrew parents had to pay redemption money to the priest of the temple to ‘redeem’ their son to be their own son.
Consider what this meant for the people of Egypt when the judgment of God fell on Pharoah (Exodus 10:1 – 13:6). By way of contrast, consider what it will mean for the church of the firstborn (Hebrews 12:23) when His judgment falls on Pharoah’s counterpart in the days that lie ahead.
Wouldn’t you rather be judged / disciplined / redeemed by God than condemned along with the world? Selah!