1 Chronicles 19:10-12 New American Bible, Revised Edition (NABRE)

10. When Joab saw that there was a battle line both in front of and behind him, he chose some of the best fighters among the Israelites and lined them up against the Arameans;

11. the rest of the army, which he placed under the command of his brother Abishai, then lined up to oppose the Ammonites.

12. And he said: “If the Arameans prove too strong for me, you must come and save me; and if the Ammonites prove too strong for you, I will save you.

1 Chronicles 19