Was afraid — Lest either their revenge or policy should prompt them to kill him. Perhaps he was the more apprehensive, because he wore Goliath's sword, which was probably well known at Gath. He now learned by experience what he afterward taught us, Psalms 118:9. It is better to trust in the Lord, than to put any confidence in princes.
Related Commentaries of 1 Samuel 21:12
1 Samuel 21:12
12 And David laid up these words in his heart, and was sore afraid of Achish the king of Gath.