Bible Verses About Oaths: God used, to show the immutability of his counsel

And I will come near to you to judgment; and I will be a swift witness against the sorcerers, and against the adulterers, and against false swearers, and against those that oppress the hireling in his wages, the widow, and the fatherless, and that turn aside the stranger from his right, and fear not me, saith the LORD of hosts.

Thou shalt fear the LORD thy God, and serve him, and shalt swear by his name.

Thou shalt fear the LORD thy God; him shalt thou serve, and to him shalt thou cleave, and swear by his name.

But Jesus held his peace. And the high priest answered and said unto him, I adjure thee by the living God, that thou tell us whether thou be the Christ, the Son of God.

And I heard the man clothed in linen, which was upon the waters of the river, when he held up his right hand and his left hand unto heaven, and sware by him that liveth for ever that it shall be for a time, times, and an half; and when he shall have accomplished to scatter the power of the holy people, all these things shall be finished.