O Lord our God, grant that thy Church, following the teaching of thy servant Leo of Rome, may hold fast the great mystery of our redemption, and adore the one Christ, true God and true Man, neither divided from our human nature nor separate from thy divine Being; through the same Jesus Christ our Lord, who liveth and reigneth with thee and the Holy Spirit, one God, now and for ever.
Besides being Leo’s big day today is the 239th birthday of the United States Marine Corps.