Large Catechism: Necessity of Holy Days (I 78-86)

"This is the simple meaning of the commandment: People must have holidays. Therefore, such observances should be devoted to hearing God's Word so that the special function of this day of rest should be the ministry of the Word for the young and the mass of poor people. Yet the resting should not be strictly understood to forbid any work that comes up, which cannot be avoided" (86).