 From 1 July 1909 to 27 February 1921 he served as chaplain to Zweibrücken prison, an extremely difficult and thankless pastoral post.From 4 August 1914 Weis was also pastor to a field hospital, then pastor to 12th Bavarian Infantry Division (known as "the Iron Division" for its bravery and toughness).He published his memoirs of his time with 12th Division in 1917 as "Mit einer bayerischen Division durch Rumänien" ("With a Bavarian Division through Romania"), along with his postcards from the front, with the proceeds from both works given to soldiers' charities.