Many of us are accustomed to carrying personal items with us in our pockets. The robes customarily worn in Old Testament times did not contain pockets (David’s use of a pouch, 1 Samuel 17:49). Those who wished to carry something on their person without using a pouch would tuck the item behind the belt worn around the robe. To hide that personal item from public view, the robe was wide enough to create a fold behind the belt. Shaking out the fold of a garment was then the equivalent of turning our pockets inside out.
13 I also shook out the fold of my garment and said, “So may God shake out every man from his house and from his labor who does not keep this promise. So may he be shaken out and emptied.” And all the assembly said “Amen” and praised the LORD. And the people did as they had promised.