13When God made a promise to Abraham, because he had no one greater by whom to swear, he swore by himself, 14saying, “I will surely bless you and multiply you.” 15And thus Abraham, having patiently endured, obtained the promise. 16Human beings, of course, swear by someone greater than themselves, and an oath given as confirmation puts an end to all dispute. 17In the same way, when God desired to show even more clearly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it by an oath, 18so that through two unchangeable things, in which it is impossible that God would prove false, we who have taken refuge might be strongly encouraged to seize the hope set before us. 19We have this hope, a sure and steadfast anchor of the soul, a hope that enters the inner shrine behind the curtain, 20where Jesus, a forerunner on our behalf, has entered, having become a high priest forever according to the order of Melchizedek. (Hebrews 6:13-20, NRSV)
God swore to Abraham by himself and on himself. We as humans sometimes do not take the word of others as truth and ask them to swear an oath on something greater than themselves.
But through God we are given a sure and certain hope and a promise that is sure.
So don’t swear by anything and know that God’s promise is firm. A solid foundation on which to build our lives.