From Manners and Customs of the Bible:

“In your purses,” is literally “in your girdles,” (ζώνας) It is quite common to use the folds of the girdle as a pouch, or pocket, for the reception of money. Money is also sometimes carried in a bag, which is. put into the girdle. This is referred to in the parallel passage in Luke, where the word rendered “purse” (βαλαντιον) signifies a bag.