How can Jesus be both root and offspring of David if he was only a man and did not pre-exist his incarnation?

There is a related question here: hermeneutics.stackexchange.com/questions/56196/… We are told in various imagery that Messiah would come in the line of David and be a branch or rod that sprouts from Jesse's roots: > And there shall come forth a rod out of the stem of Jesse, and a Branch shall grow out of his roots: And the spirit of the Lord shall rest upon him, the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and of the fear of the Lord; - Isaiah 11:1-2 > Hear now, O Joshua the high priest, thou, and thy fellows that sit before thee: for they are men wondered at: for, behold, I will bring forth my servant the Branch. - Zechariah 3:8 > And speak unto him, saying, Thus speaketh the Lord of hosts, saying, Behold the man whose name is The Branch; and he shall grow up out of his place, and he shall build the temple of the Lord: - Zechariah 6:12 Later, in Revelation, we are told that Jesus is the root of David: > And one of the elders saith unto me, Weep not: behold, the Lion of the tribe of Judah, the Root of David, hath prevailed to open the book, and to loose the seven seals thereof. - Revelation 5:5 And then Jesus himself claims to be both the root and the offspring of David: > I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star. - Revelation 22:16 This is much like when Jesus asked about whose son the Christ is "“How is it then that David, in the Spirit, calls him Lord, saying, “‘The Lord said to my Lord, “Sit at my right hand, until I put your enemies under your feet”’? If then David calls him Lord, how is he his son?” (Matthew 22:43-45). For those who believe Jesus did not pre-exist his incarnation, How can Jesus be the root of David if he is David's offspring?