Map of Syria, Palestine, Turkey, and Mesopotamia from the Baedeker 1912 travel guide Palestine and Syria with Routes through Mesopotamia and Babylonia and with the Island of Cyprus.
"3. The Seventh Army pertaining to Jilderim will be transported to the Sinai front. The troops now on the Sinai Front will be under the Army Group Jilderim as long as the Seventh Army remains on the Sinai front.4. The Army Group Jilderim will conduct its operations independently on the Sinai front and in the separate Sanjak of Jerusalem, but Jilderim will keep the commander in chief in Syria and West Arabia informed."
Excerpt from the order of Turkish War Minister Ismail Enver to his commanders in October, 1917, quoted by German General and commander of the Germany military mission to Turkey Liman von Sanders. Sanders notes that the Group Jilderim — Turkish for 'lightning' — was organized not with military assistance from German officers as was common during the war, but as a German army group with German officers and a German commander. The army was being collected at Aleppo, whence it could be directed to Mesopotamia and the reconquest of Baghdad or to Palestine for the defense of Gaza and Jerusalem, or for an offensive against Egypt. Enver chose the latter.
Five Years in Turkey by Liman von Sanders, page 180, publisher: The Battery Press with War and Peace Books, publication date: 1928 (originally)
1917-10-08, October, 1917, Liman von Sanders, von Sanders, Sanders, Enver, Jerusalem