David's arrival in the city of Mahanaim marks a sudden turning point in his desperate escape from his son Absalom. After enduring a period of deep isolation where he bore the punishment for his past actions, hope appears as supporters step forward to help him [מלבי״ם]. Three righteous men coordinate with one another, traveling from their distinct locations to bring essential supplies to David and his exhausted followers. Because David had fled Jerusalem with absolutely nothing, these men provide his camp with desperately needed equipment, bedding, and food [רלב״ג, אברבנאל].
The identity of the first of these three men, Shobi son of Nahash, is a subject of discussion. According to traditional sources, this man is actually Hanun son of Nahash, the former king of the Ammonites [רש״י, אברבנאל]. Because David had previously dealt a crushing defeat to the Ammonites, some explain that Hanun repented and converted, and as a result, David spared his life [רד״ק, חומת אנך, אברבנאל]. Another possibility is that Shobi was simply the son of the Ammonite king, whom David had left with some local authority following the conquest [ביאור שטיינזלץ]. Conversely, others reject an Ammonite origin entirely, suggesting that Shobi was an Israelite who had settled in the Ammonite capital after David conquered it [רד״ק, אברבנאל]. The other two benefactors are Machir son of Ammiel, who arrived from his city of Lo-debar, and Barzillai the Gileadite, who came from a city in the land of Gilead called Rogelim [רד״ק, אברבנאל, ביאור שטיינזלץ].
This sudden gathering carries a deep spiritual significance. When David first saw these men approaching, he was filled with fear. However, he immediately realized that God was actively working on His behalf, transforming former enemies into allies who sought peace with him [אברבנאל]. Tradition adds a profound layer to this moment, teaching that this event, along with all the severe hunger, thirst, and hardship experienced by the fleeing camp, took place on the Day of Atonement [אברבנאל].