Directed by a divine message through the prophet Gad, David is told to leave his current place of refuge and return to the territory of his own tribe. He promptly obeys this command, which carries both practical and spiritual weight. The instruction to abandon his stronghold serves a dual purpose. On a practical level, the prophet is telling David that he should not live in a foreign land as if he were an enemy of Israel [ביאור שטיינזלץ]. On a spiritual level, it acts as a warning against remaining near Moab and relying on the protective merit of his ancestor, Ruth the Moabite [חומת אנך]. Instead, he must return to the land of Judah so that he can lean on the merit of his Judean ancestors for protection and salvation [חומת אנך].
The primary approach among commentators is that returning to Judah offered a clear strategic advantage. Because it was his native tribe, David was surrounded by friends and acquaintances. This familiar environment provided a natural shield, as the local residents could warn him in advance of any attempts by Saul to capture him, giving him time to escape [רד״ק, אברבנאל, ביאור שטיינזלץ]. In fact, Saul did not even attempt to hunt him down while he remained in this supportive area. It was only later, when David relocated to Keilah, a border city far from his loyal network, that Saul resumed his pursuit [רד״ק, אברבנאל].
Beyond securing his personal safety and showing a willingness to endure his hardships within his homeland [ביאור שטיינזלץ], this relocation served as a prophetic sign. It foreshadowed that at the beginning of his reign, David would rule exclusively over the tribe of Judah for seven years [אברבנאל].
Following the prophet's command, David travels to the forest of Hereth. While the simple understanding is that Hereth is merely the name of the location, an additional layer of meaning suggests the area was originally completely dry and barren. In honor of David's arrival, God brought water to the region, causing the once arid forest to bloom and flourish [רד״ק].