'Robes' in the Bible

Now the king of Israel and Jehoshaphat the king of Judah sat each on his throne, arrayed in their robes, and they were sitting in an open place at the entrance of the gate of Samaria; and all the prophets were prophesying before them.

The king of Israel said to Jehoshaphat, "I will disguise myself, and go into the battle; but you put on your robes." So the king of Israel disguised himself; and they went into the battle.