שמואל ב, פרק י״ח, פסוק ב׳

Preparing for battle, David organizes his military forces with a clear strategy. He divides the army into three distinct divisions, assigning a third of the troops to a different trusted commander [מלבי״ם, ביאור שטיינזלץ]. The first group is entrusted to Joab, and the second to his brother, Abishai. The final third is placed under the leadership of Ittai the Gittite, a loyal supporter of the king who likely commanded the foreign troops [ביאור שטיינזלץ].

Once the forces are divided, David addresses his men and declares his desire to personally join them on the battlefield [מלבי״ם]. By stepping forward as the supreme commander, he upholds the tradition of Israelite leaders who led their armies directly into combat [ביאור שטיינזלץ].