A white handkerchief
It is told of General Gordon, that each morning, during his journey in the Soudan country, for half an hour there lay outside his tent a white handkerchief. The whole camp knew well what it meant, and looked upon the little signal with the utmost respect; no foot dared cross the threshold of that tent while the little guard lay there. No message, however pressing, was to be delivered. Matters of life and death must wait until the white signal was taken away. Everybody in the camp knew that God and Gordon were communing together.