Rev.5:5 – and one of the elders said to me, “Stop weeping; behold, the Lion that is from the tribe of Judah, the Root of David, has overcome so as to open the book and its seven seals.”
The facets of the glory of God seen in Christ are limitless. The book of Revelations is filled with titles and names speaking of the Lord, each of them point to one of His attributes. This phrase, Root of David, tends to be overlooked but is full of meaning referring to the deity and humanity of Christ. As to His deity, Christ is the root that David sprang from. How can that be? Christ is the Creator of David. This reminds us of the question Jesus posed to the Pharisees in Matthew 22:44,45, ‘THE LORD SAID TO MY LORD, “SIT AT MY RIGHT HAND, UNTIL I PUT YOUR ENEMIES BENEATH YOUR FEET”’? “If David then calls Him ‘Lord,’ how is He his son?”
This is the great mystery of the manhood and deity of Christ. David came from the Lord but the Lord also came from David. Here are some thoughts from the JFB Commentary and the ESV Study Bible.
“Root of David — (Isaiah 11:1, 10). Not merely “a sucker come up from David’s ancient root”, but also including the idea of His being Himself the root and origin of David. Hence He is called not merely Son of David, but also David. He is at once “the branch” of David, and “the root” of David, David’s Son and David’s Lord, the Lamb slain and therefore the Lion of Juda: about to reign over Israel, and thence over the whole earth.”
“But now he is also called the Root of David, because Jesus is not only the royal descendant (Rev. 22:16) but also the source of David’s rule (Mark 12:35–37; cf. “root of Jesse,” Rom. 15:12).”
In the book of Revelations John sees this mystery of humanity and deity from a different perspective. John had see Christ on earth as a man and was amazed at the glimpses of deity seen in Him here. As John is caught up into heaven he is absolutely thunderstruck by the humanity of Christ in His glorified state. Yes, a man is seated on the throne ruling all things. All of creation responds to Him and bows in worship before His throne.