Albert Barnes Commentary Revelation 2:18

"And to the angel of the church in Thyatira write: These things saith the Son of God, who hath his eyes like a flame of fire, and his feet are like unto burnished brass:" — Revelation 2:18 (ASV)

And unto the angel of the church. (See Barnes' Notes on Revelation 1:20)

These things saith the Son of God. This is the first time, in these epistles, that the name of the speaker is referred to. In each other instance, there is merely some attribute of the Saviour mentioned.

Perhaps the severity of the rebuke contemplated here made it appropriate that there should be a more impressive reference to the speaker's authority; for this reason, he is introduced as the "Son of God." It is not a reference to him as the "Son of man"—the common title he gave himself when on earth—for that might have suggested his humanity only and would not have conveyed the same impression regarding his authority. Instead, it is to himself as sustaining the rank and having the authority of the Son of God—one who, therefore, has a right to speak and a right to demand that what he says shall be heard.

Who hath his eyes like unto a flame of fire. (See Barnes' Notes on Revelation 1:14)

Before the glance of his eye all is light, and nothing can be concealed from his view. Nothing would be better suited to inspire awe then, as is also true now, than such a reference to the Son of God as being able to penetrate the secret recesses of the heart.

And his feet are like fine brass. (See Barnes' Notes on Revelation 1:15)

Perhaps this is indicative of majesty and glory as he walked among the churches.