The quote in Hebrews is from Psalm 108 which is entirely about Jehovah/Yahweh as indicated by the LORD being in caps and the reference to God as Creator.
Psa 102:18 This shall be written for the generation to come: and the people which shall be created shall praise the LORD.
Psa 102:19 For he hath looked down from the height of his sanctuary; from heaven did the LORD behold the earth;
Psa 102:20 To hear the groaning of the prisoner; to loose those that are appointed to death;
Psa 102:21 To declare the name of the LORD in Zion, and his praise in Jerusalem;
Psa 102:22 When the people are gathered together, and the kingdoms, to serve the LORD.
Psa 102:23 He weakened my strength in the way; he shortened my days.
Psa 102:24 I said, O my God, take me not away in the midst of my days: thy years are throughout all generations.
Psa 102:25 Of old hast thou laid the foundation of the earth: and the heavens are the work of thy hands.
Psa 102:26 They shall perish, but thou shalt endure: yea, all of them shall wax old like a garment; as a vesture shalt thou change them, and they shall be changed:
Psa 102:27 But thou art the same, and thy years shall have no end.