In 1933 Van Paassen traveled incognito to the Dome of the Rock, a famous Islamic shrine in Jerusalem. He was accompanied by a British Intelligence officer, and both smeared their faces and hands with burnt cork to give them an Arab appearance. They also wore long white garments to give them a "Hadjihs" appearance. Their evasiveness was a necessity, for nonbelievers were (and still are) not allowed in areas that are considered to be the holiest places in the world of Islam. The purpose of their venture was to get an inside look at the radical movement by listening to what the Mullahs were preaching in regards to the political turmoil that was taking place in then British controlled Palestine. Three years later The Great Uprising took form. This redoubled political violence was in part planned by the Grand Mufti of Jerusalem, Mohammad Amin al-Husayni, whom Van Paassen had interviewed in 1929 about his incitement of the bloody uprising that year against the Jews in Palestine.