The Fourth Commandment: Our Catechism, Calvin, and Ursinus

Does the way in which the Heidelberg Catechism deals with the fourth Commandment in Lord’s Day 38 leave you longing for more? The catechism does not say anything about what is forbidden on the Sabbath. Is this an issue? This article looks at Calvin's perspective on the fourth commandment and how this perspective influenced Ursinus.