שמואל ב, פרק ט״ו, פסוק כ״ב

Faced with absolute loyalty, a leader must sometimes accept the sacrifices of his followers. After Ittai the Gittite expresses his unwavering devotion and refuses to leave, David accepts his decision and allows him to join the difficult journey. David grants him official permission to cross over and join the rest of the people and the royal servants, simply because Ittai stands completely firm in his resolve to stay by David's side [רש״י].

With this approval, Ittai does not walk alone. He moves forward with all of his men and their young children. The entire Philistine battalion, along with their families, commits to the journey and merges into David's camp [ביאור שטיינזלץ].

This movement of Ittai's forces and David's entire camp takes place with a deep sense of brokenness. As they march, the people weep and mourn. Even the local inhabitants cry as they watch the king pass by in his distress. Furthermore, this journey does not lead to a safe, settled city. The camp is headed directly toward the desert, marching into a dry and empty wasteland [אברבנאל].