Oath used in Solemnizing Covenants: Between Abraham and the King of Sodom
Source: Nav
Genesis 14:22, 23
But Abram replied to the king of Sodom, “I have raised my hand to the LORD God Most High, Creator of heaven and earth, / that I will not accept even a thread, or a strap of a sandal, or anything that belongs to you, lest you should say, ‘I have made Abram rich.’