From the prepared text of his speech:
https://www.whitehouse.gov/briefings-statements/remarks-president-trump-new-york-city-veterans-day-parade/
"Roddie was in the 422nd regiment, which was overwhelmed when the Nazis launched their surprise assault. He and his men fought for three treacherous days before being taken as prisoners of war.
After they arrived at a prison camp, the German commander sent an order over the loud speaker. The Jewish-American soldiers were all told to step out of line during the roll call the next day. Knowing the terrible fate that would come to his Jewish comrades, Roddie immediately said, Were not doing that. He sent orders to have every American step out of line with their Jewish brothers-in-arms.
The next morning, 1,292 Americans stepped forward. The German commander stormed over to Roddie and said, They cannot all be Jews. Roddie stared right back; he said, We are all Jews here.
At that point, the German put a gun to Roddies head and demanded, You will order the Jews to step forward immediately or I will shoot you right now through the head. Roddie responded, Major,
you can shoot me, but youll have to kill us all. Thats something. (Applause.) The German turned red, got very angry, but put down his gun, and walked away."