Source
Soldiers of the 8th Army! The many days of fierce fighting on the wide fields between Allenstein and Neidenburg are over. You have won a crushing victory over five army corps and three cavalry divisions. More than 90,000 prisoners, countless guns and machine guns, several flags, and much other war booty are in our hands. The few remnants of the Russian Narew Army that escaped encirclement are fleeing south across the border. The Russian Wilna Army has begun its retreat from Königsberg.
Next to God Almighty, this brilliant success is due to your willingness to make sacrifices, your unsurpassed marching performance, and your outstanding bravery. I hope to be able to give you a few days of well-deserved rest. But then, with renewed strength, we will press forward with God for the Emperor, the King, and the Fatherland until the last Russian has left our dear, sorely tried home province and we have carried our victorious flags into enemy territory. Long live His Majesty the Emperor and King, hurrah!
Source: Paul von Hindenburg, Aus dem Dankerlass an die Truppen der 8. Armee nach der Schlacht von Tannenberg, August 31, 1914. Recording date: October 17, 1917. Stiftung Deutsches Rundfunkarchiv