For as the image formed in a mirror unerringly reflects all the acts and movements of him who gazes on it, so would Wisdom have herself to be understood when she is called the stainless mirror of the power and working of the Father: as the Lord Jesus Christ also, who is the Wisdom of God, declares of Himself when He says, “The works which the Father doeth, these also doeth the Son likewise.” And again He says, that the Son cannot do anything of Himself, save what He sees the Father do. As therefore the Son in no respect differs from the Father in the power of His works, and the work of the Son is not a different thing from that of the Father, but one and the same movement, so to speak, is in all things, He therefore named Him a stainless mirror, that by such an expression it might be understood that them is no dissimilarity whatever between the Son and the Father.
Origen
On First Principles, Book I
Chapter II