Volume 2 (That is, Year 2) of the English translation of Der Lutheraner, published by C.F.W. Walther in 1845, is now available. Subscribe at http://markvpublications.com/
Excerpt from Volume 2, No. 2:
Walk in Your Vocation.
God's Word, command and work alone must be regarded, and that alone honored and praised and what comes along outside of God's Word and Command must all be reproached as something else. Now when a maid tends to the chickens, a wife bears her children, a husband attends the labor of his hands, a prince or a lord has wicked fools knocked on the head, they should all be approved regardless of their station and say: God has done that. But even if you had the ability to save all the world with your preaching and yet you did not have a command to do so, just leave that alone, for you would transgress the legitimate Sabbath and it would not be pleasing to God.
--Luther on Exodus 20:8-11