Green marking with a dagger stabbing a Magen David.  Historical status as a flag is unknown, possibly dubious, but as a historical emblem or insignia, see image [1] linked from  [2]
originally uploaded as File:Arab Liberation Army.svg, version 20:03, 5 October 2010, its source is http://www.ynet.co.il/PicServer2/02022009/2084251/12-Zklarts_043_wh.jpg
Vallecyofdawn