Hebrews 1:5

For--substantiating His having "obtained a more excellent name than the angels." unto which--A frequent argument in this Epistle is derived from the silence of Scripture (Heb 1:13; Heb 2:16; Heb 7:3, Heb 7:14) [BENGEL]. this day have I begotten thee-- (Psa 2:7). Fulfilled at the resurrection of Jesus, whereby the Father "declared," that is, made manifest His divine Sonship, heretofore veiled by His humiliation (Act 13:33; Rom 1:4). Christ has a fourfold right to the title "Son of God"; (1) By generation, as begotten of God; (2) By commission, as sent by God; (3) By resurrection, as "the first-begotten of the dead" (compare Luk 20:36; Rom 1:4; Rev 1:5); (4) By actual possession, as heir of all [BISHOP PEARSON]. The Psalm here quoted applied primarily in a less full sense to Solomon, of whom God promised by Nathan to David. "I will be his father and he shall be my son." But as the whole theocracy was of Messianic import, the triumph of David over Hadadezer and neighboring kings (2Sa. 8:1-18; Psa 2:2-3, Psa 2:9-12) is a type of God's ultimately subduing all enemies under His Son, whom He sets (Hebrew, "anointed," Psa 2:6) on His "holy hill of Zion," as King of the Jews and of the whole earth. the antitype to Solomon, son of David.

— Jamieson-Fausset-Brown Commentary (public domain)