The Messiah would be the Son of God.
OT Prophecy NT Fulfillment
1 Chronicles 17:13–14
[13] I will be his father, and he shall be my son: and I will not take my mercy away from him, as I took it from him that was before thee.
[14] But I will settle him in mine house and in my kingdom for ever: and his throne shall be established for evermore.
Matthew 3:16–17
[16] And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him.
[17] And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.

John 12:28–30
[28] Father, glorify thy name. Then came there a voice from heaven, saying, I have both glorified it, and will glorify it again.
[29] The people therefore, that stood by, and heard it, said that it thundered: others said, An angel spake to him.
[30] Jesus answered and said, This voice came not because of me, but for your sakes.
Tanakh – Ketuvim – 1 Chronicles 17:13–14
[13] I will be to him for a father, and he shall be to Me for a son; and I will not take My mercy away from him, as I took it from him that was before thee.
[14] But I will settle him in My house and in My kingdom for ever; and his throne shall be established for ever.
Hebrew OT – 1 Chronicles 17:13–14
[17:13–14] אֲנִי אֶהְיֶה־לוֹ לְאָב וְהוּא יִהְיֶה־לִי לְבֵן
וְחַסְדִּי לֹא־אָסִיר מֵעִמּוֹ כַּאֲשֶׁר הֲסִירוֹתִי מֵאֲשֶׁר הָיָה לְפָנֶיךָ
וַהֲעֲמַדְתִּיו בְּבֵיתִי וּבְמַלְכוּתִי עַד־עוֹלָם
וְכִסְאוֹ יִהְיֶה נָכוֹן עַד־עוֹלָם