'Oath' in the Bible
Whereupon he promised with an oath to give her whatsoever she would ask.
And again he denied with an oath, I do not know the man.
Therefore being a prophet, and knowing that God had sworn with an oath to him, that of the fruit of his loins, according to the flesh, he would raise up Christ to sit on his throne;
But do not thou yield unto them: for there lie in wait for him of them more than forty men, which have bound themselves with an oath, that they will neither eat nor drink till they have killed him: and now are they ready, looking for a promise from thee.
For men verily swear by the greater: and an oath for confirmation is to them an end of all strife.
Wherein God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed it by an oath:
And inasmuch as not without an oath he was made priest:
(For those priests were made without an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou art a priest for ever after the order of Melchisedec:)
For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, maketh the Son, who is consecrated for evermore.
But above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea; and your nay, nay; lest ye fall into condemnation.