John Gill Commentary Isaiah 21:15

"For they fled away from the swords, from the drawn sword, and from the bent bow, and from the grievousness of war." — Isaiah 21:15 (ASV)

For they fled from the swords of their enemy, whom they could not withstand; perhaps the Assyrian army. They fled from the drawn sword, just ready to be sheathed in them, and from the bent bow, just going to let the arrow fly at them, and from the grievousness of war, too heavy for them to bear.