שמואל א, פרק י״ח, פסוק י״ב

As a bout of depression passes, a deep sense of fear and jealousy takes hold of Saul. He suffers from his own personal decline while watching the young and talented David succeed and grow right before his eyes [ביאור שטיינזלץ]. This fear is rooted in a sharp contrast. Saul realizes that God is with David, while at the exact same time, he experiences the painful reality that God's spirit has departed from him [מלבי״ם].

The tangible proof of God's presence is evident in David's miraculous rescue. The fact that David manages to evade Saul's attacks twice, seemingly without any intention or special effort, makes it undeniably clear to Saul that David is receiving direct protection from God [מצודת דוד].