"Thou art My Son; this day have I begotten Thee." Psalm 2:7

What is the significance of this verse quoted three times in the New Testament?

Acts 13:33 - The Son is the Potentate
Hebrews 5:5 - The Son is the Priest
Hebrews 1:5 - The Son is the Prophet

Read Part 1, Part 2, Part 3, Part 4.