Stand firm therefore, having girded your loins with truth, (Ephesians 6:14)
The Roman soldier always wore a tunic, an outer garment that served as his primary clothing. It was usually made of a large, square piece of material with holes cut out for the head and arms. Ordinarily it draped loosely over most of the soldier's body. Since the greatest part of ancient combat was hand–to–hand, a loose tunic was a potential hindrance and even a danger. Before a battle it was therefore carefully cinched up and tucked into the heavy leather belt that girded the soldier's loins.
The ordinary citizen of the Near East had a similar problem with his robe. When he was in a hurry or had heavy work to do, he either took the robe off or tucked it around his waist. As God prepared the children of Israel to eat the Passover meal before they left Egypt, He instructed Moses to tell them, “Now you shall eat it in this manner: with your loins girded, your sandals on your feet, and your staff in your hand; and you shall eat it in haste” (Ex. 12:11). Concerning His second coming, Jesus tells us to “be dressed in readiness” (Luke 12:35), which is literally, “have your loins girded.” Peter used the same expression when he said, “Therefore, gird your minds [lit., “gird up the loins of your minds”] for action, keep sober in spirit, fix your hope completely on the grace to be brought to you at the revelation of Jesus Christ” (1 Pet. 1:13). Girding the loins was a mark of preparedness, and the soldier who was serious about fighting was sure to secure his tunic with his belt...