E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
War of the Meal-sacks.
After the battle of Beder, Abu Sofian summoned two hundred fleet horsemen, each with a sack of meal at his saddle-bow (the scanty provision of an Arab for a foray), and sallied forth to Medina. Mahomet went forth at the head of a superior force to meet him, and Abu Sofian with his horsemen, throwing off their meal-sacks, fled with precipitation.