When Joab saw that the battle would be fought on two fronts, he chose some of Israel’s best men and deployed them against the Arameans. ¹ 

So David again asked God what he should do. ¹  This time ²  God told him, “Don’t march up after them; circle around them and come against them in front of the trees. ³ 

They hired 32,000 chariots, along with the king of Maacah and his army, who came and camped in front of Medeba. The Ammonites also assembled from their cities and marched out to do battle.

When you hear the sound of marching in the tops of the trees, then attack. ¹  For at that moment the Lord is going before you to strike down the army ²  of the Philistines.”

Shebaniah, Joshaphat, Nethanel, Amasai, Zechariah, Benaiah, and Eliezer the priests were to blow the trumpets before the ark of God; Obed-Edom and Jehiel were also guardians ¹  of the ark.