Q. 56. What is the reason annexed to the third commandment?
A. The reason annexed to the third commandment is that however the breakers of this commandment may escape punishment from men, yet the Lord our God will not suffer them to escape his righteous judgment.
Deuteronomy 28:58,59 If you are not careful to do all the words of this law that are written in this book, that you may fear this glorious and awesome name, the LORD your God, then the LORD will bring on you and your offspring extraordinary afflictions, afflictions severe and lasting, and sicknesses grievous and lasting.
I Samuel 4:11 And the ark of God was captured, and the two sons of Eli, Hophni and Phinehas, died.