The conclusion of the confrontation brings a deep sense of relief for David, as he is spared from fighting against his own people. Despite the respectful manners he showed toward Achish, David had no real desire to participate in the war and heads home with a joyful heart. His standing with Achish likely forced him to join the military campaign in the first place. He may have even considered doing exactly what the Philistine commanders suspected, planning to attack them from within during the battle depending on how events unfolded. Ultimately, the Philistine demand to send him away rescues him from a highly awkward and complicated situation [ביאור שטיינזלץ].
Rising early in the morning, David and his men begin their journey back to the land of the Philistines, specifically heading to the city of Ziklag [ביאור שטיינזלץ]. David's readiness to wake up early and leave is directly tied to how the dismissal is presented. Earlier, when Achish told only David to return, David refused to be appeased. It is only when Achish explicitly includes David's men in the order to return that David is satisfied and agrees to depart immediately [אברבנאל].
As David makes his exit, the Philistine army continues its advance northward toward Jezreel, moving directly toward the site of the impending battle [ביאור שטיינזלץ].