Saint Paul wrote to the Philippians: "And the peace of God, which passeth all understanding, shall keep your hearts and minds through Christ Jesus." (4:7, Authorized Version)

This catchy phrase is perhaps more familiar to Episcopal children as it is echoed in "the birthday prayer" used in many congregations: ""Watch over thy children, O Lord, as their days increase; bless and guide them wherever they may be. Strengthen them when they stand; comfort them when discouraged or sorrowful; raise them up if they fall; and in their hearts may thy peace which passeth understanding abide all the days of their lives; through Jesus Christ our Lord. Amen." (1979 Book of Common Prayer [American]).

This peace is not something desired by all, e.g. Helen Keller, who said: "I do not want the peace which passeth understanding, I want the understanding which bringeth peace."

No, I can't give "Max a quick refresher ... on the peace that passeth understanding" because it PASSETH UNDERSTANDING!