A. Joab told his brother that they should help each other if needed, and that they should be strong because Yahweh will do what is good for his people. [19:12-13]
Q? Why did the army of Ammon flee back to their city?
A. The army of Ammon saw that the Arameans fled before the army of Israel, and so they ran back to their city. [19:14-15]
Q? Why did David gather all Israel together and arrange for battle against the Arameans?
A. David heard that the Arameans sent for reinforcements. [19:16-17]
Q? Why were the people of Aram no longer willing to help the Ammonites?
A. They no longer helped the Ammonites when David killed 47 thousand of their men and the commander of the army. [19:18-19]