God is both the Lord of the covenant and Servant of the covenant.
“All we like sheep have gone astray; we have turned—every one—to his own way; and the Lord has laid on him the iniquity of us all. He was oppressed, and he was afflicted, yet he opened not his mouth; like a lamb that is led to the slaughter, and like a sheep that before its shearers is silent, so he opened not his mouth. By oppression and judgment he was taken away; and as for his generation, who considered that he was cut off out of the land of the living, stricken for the transgression of my people?” —Isaiah 53:6-8
“So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath, so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us.” —Hebrews 6:17-18