Divine rescue often happens as a sharp, sudden shift from a feeling of suffocation and confinement to a state of total freedom and relief. The primary approach among commentators is that being brought out into a wide, open space represents being extracted from deep trouble and placed in a secure, expansive environment. This experience of newfound freedom serves as the direct opposite of the intense distress and confinement experienced earlier during times of crisis [אבן עזרא]. The very nature of this salvation involves being pulled out of narrow, restrictive straits into safety.
These vivid images capture how David was saved through God's personal providence and miraculous intervention [ביאור שטיינזלץ]. Rather than just a conceptual metaphor, this rescue connects to very real, physical events in David's life [אלשיך]. For instance, it reflects his escape from the city of Keilah, which was heavily fortified with doors and bars and felt like a prison. Alternatively, it points to his narrow escape from a cave, just moments before King Saul and his soldiers could discover him and lay siege.
Ultimately, the reason behind this profound rescue stems entirely from divine will. God pulled David out of danger not as a reward for David's own personal righteousness, but simply because God favored him and desired to save him [אלשיך].