Brewer's: V. D. M. I. A. E
(Verbum Dei manet in aeternum). The word of God endureth for ever. The inscription on the livery of the servants of the Duke of Saxony and Landgrave of Hesse, the Lutheran princes, at the Diet of Spires in 1526.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894