1 Samuel 27:10 - Joseph Benson’s Commentary on the Old and New Testaments

David said, Against the south of Judah, &c. David expressed himself thus ambiguously that Achish might suppose he had assaulted the land of Judah; whereas he had only fallen upon those people who bordered on that land. His words, therefore, though not directly false, (all those people actually dwelling on the south of Judah,) yet being ambiguous, and intended to convey an erroneous idea, were very contrary to that simplicity which became David, both as a prince and as an eminent professor of the true religion. The fidelity of Achish to him, and the confidence he put in him, aggravates his sin in thus deceiving him; which David seems peculiarly to reflect on when he prays, “Remove from me the way of lying.”