To achieve the "perfect peace" spoken of by the prophet Isaiah, we must understand what it means to “stay one’s mind on God.” In Isaiah 26:3, "You keep him in perfect peace whose mind is stayed on you, because he trusts in you," the phrase "stayed on you" implies a steadfast, unwavering focus and trust in God. It is more than just occasional thoughts about God; it is a deliberate and continuous mental posture that centers on who God is — His character, His promises, His purposes, and His presence https://www.monergism.com/reformation-theology/blog/you-keep-him-perfect-peace-whose-mind-stayed-you