And I saw another mighty angel come down from heaven, clothed with a cloud: and a rainbow was upon his head, and his face was as it were the sun, and his feet as pillars of fire: Another mighty angel - Either Christ or his representative; clothed with a cloud; a symbol of the Divine majesty.
A rainbow was upon his head - The token of God's merciful covenant with mankind.
His face was as it were the sun - So intensely glorious that it could not be looked on.
His feet as pillars of fire - To denote the rapidity and energy of his motions, and the stability of his counsels.