What is the meaning of Psalm 2:7?

[The Learner]

Psalm 2:7
I will declare the decree: the Lord hath said unto me, Thou art my Son; this day have I begotten thee.

Acts 13:33
God hath fulfilled the same unto us their children, in that he hath raised up Jesus again; as it is also written in the second psalm, Thou art my Son, this day have I begotten thee.

How does Acts say it was a fulfillment of the Psalm 2:7?

Hebrews 1:5
For unto which of the angels said he at any time, Thou art my Son, this day have I begotten thee? And again, I will be to him a Father, and he shall be to me a Son?

I believe Jesus as the Son of God is the creator. Does, the text somehow relate to kingship?

 

[The Learner]

The thread that brought up this question in my mind is closed, thus I could not ask this there.

 

[MatthewG]

Maybe, but I can not remember if it was after resurrection that Jesus Christ is then known as the Begotten Son. Another scripture to give Hebrews 5:5.