In this week’s installment from Off the Record with Martin Luther, Luther compares hypocrites to ostriches:

2154. The ostrich buries its head in the sand and thinks it is completely covered and concealed, so that no one can see it. Likewise, the hypocrites seize upon some particular good work, and believe they have covered all the dirt of their sins and completely hidden them, and that they appear beautifully adorned and righteous before God. (p. 331)