Jeremiah 10:7
Who would not fear You, O King of the nations? Indeed it is Your due! For among all the wise men of the nations And in all their kingdoms, There is none like You.
Isaiah 33:22
For the LORD is our judge, The LORD is our lawgiver, The LORD is our king; He will save us—
Isaiah 44:6 "This is what the LORD says--Israel's King and Redeemer, the LORD Almighty: I am the first and I am the last; apart from me there is no God.
1 Timothy 6:15
which God will bring about in his own time—God, the blessed and only Ruler, the King of kings and Lord of lords,
Revelation 17:14
They will wage war against the Lamb, but the Lamb will triumph over them because he is Lord of lords and King of kings—and with him will be his called, chosen and faithful followers.”
Revelation 19:16
On his robe and on his thigh he has this name written: King of kings and lord of lords.
Do you see how God the Father is called King in the Old Testament?
Do you see how Jesus is called the King in the New Testament?
Jesus is God the Father come to earth in the flesh as a Son.