God needs to take no oaths since His words are always reliable. So when He chooses to take one, it’s clearly a moment in history in which He wants us to know with absolute certainty that He will do what He’s said.
God’s oath
Anchored
Abraham started life not knowing God. But in his later years, God called this elderly, childless man to move to Canaan where he would be blessed with family and home. Yet having given Abraham a son – Isaac – God then demanded him back via sacrifice