David cometh to Nob to Ahimelech the priest; pretendeth secret business from Saul; asketh bread: Ahimelech giveth him the shew-bread, 1-6. Doeg seeth this, 7. David asketh arms: Ahimelech giveth him Goliath’s sword, 8, 9. David cometh to Achish; is known; and afraid; feigneth himself mad, 10-13. Achish is angry with his servants for bringing him, 14, 15.
Thomas Brooks' Privy Key of Heaven: 'In 1 Samuel 21, you may read of David's round lies, and of his other failings, infirmities, and unseemly carriages before Achish, king of Gath, and for which he was turned out of the king's presence, under the notion of a madman; and yet at that very time he prays, and prevails with God for favour, mercy, and deliverance: Psalm 34:4, "I sought the Lord, and he heard me, and delivered me out of all my fear." But when was this? Read the title of the psalm, and you shall find it: "A psalm of David, who changed his behaviour before Abimelech, who drove him away, and he departed."'
Matthew Henry: 'David has now quite taken leave both of Saul's court and of his camp, has bidden farewell to his alter idem—his other self, the beloved Jonathan; and henceforward to the end of this book he is looked upon and treated as an outlaw and proclaimed a traitor. We still find him shifting from place to place for his own safety, and Saul pursuing him. His troubles are very particularly related in this and the following chapters, not only to be a key to the Psalms, but that he might be, as other prophets, an example to the saints in all ages, "of suffering affliction, and of patience," and especially that he might be a type of Christ, who…
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