Revelation 10:1
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: 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:
The mighty angel coming down from heaven is Jesus Christ Himself, coming down to instruct John. The rainbow upon His head is God's glory and mercy resting upon Him for the benefit of repentant people, encompassing the earth and resting also around the throne. When human sin and wickedness provoke God's wrath, Christ intercedes for humanity and points to the rainbow in the cloud as evidence of God's mercy and compassion.
His setting His right foot on the sea and His left on the dry land denotes His supreme power and authority over the whole earth and shows the part He acts in the closing scenes of the great controversy with Satan. That controversy has grown stronger from age to age and will continue to the concluding scenes, when the working of the powers of darkness reaches its height and Satan united with evil men will deceive the whole world and the churches who receive not the love of the truth. Yet the mighty Angel demands attention and cries with a loud voice, to show the power and authority of His voice to those who have united with Satan to oppose the truth.
His position with one foot on the sea and the other on the land signifies the wide extent of the proclamation of the message, which will cross the broad waters and be proclaimed in other countries, even to all the world. Standing with one foot on the sea He proclaims with a most solemn oath that time should be no longer, meaning the first and second angels' messages were to be proclaimed and to do their specific testing work before any further advanced truth was revealed. The seven thunders are the special light delineating events to transpire under those two messages, which John heard but was commanded not to write because it was not best for the people to know them and faith must be tested. Daniel and Revelation are one, Daniel a sealed prophecy and Revelation an opened revelation.