John Wesley on Philippians 4:7

And the peace of God - That calm, heavenly repose, that tranquility of spirit, which God only can give. Which surpasseth all understanding - Which none can comprehend, save he that receiveth it. Shall keep - Shall guard, as a garrison does a city. Your hearts - Your affections. Your minds - Your understandings, and all the various workings of them; through the Spirit and power of Christ Jesus, in the knowledge and love of God. Without a guard set on these likewise, the purity and vigour of our affections cannot long be preserved.