Later, however, I have added brief allegories, almost for every chapter. This is not because I attach great importance to them, but I want to forestall the silly attempts at allegorical interpretation that some make. We see that Jerome, Origen, and other ancient writers did not employ a sufficiently felicitous and helpful method of devising allegories, since they direct everything to manners and works, whereas everything should rather be applied to the Word and to faith. Indeed, they exercised themselves in pure allegories, namely, in the talk of crazy persons. Lest readers be deceived by a false idea in allegories, I reckoned it worth the effort to show them that it is a proper allegory when, so far as possible, they discover in every allegory the ministry of the Word or the progress of the Gospel and of faith. For this is the purpose of whatever figures or meanings there are in the Law and the people of Moses.
Luther’s works, vol. 9: Lectures on Deuteronomy 1525