Hastings' Dictionary of the Bible (1898)
OATH, a solemn affirmation, made with an appeal to the Deity in attestation of its truth. Heb 6:16. The custom of taking oaths was in vogue in the earliest patriarchal times. Gen 21:23, but their use is not confined to men. God also has bound himself by oaths. Acts 2:30; Gen 26:3; Deut 29:12, etc. Their use was the subject of legislation, Ex 20:7; Lev 19:12, and our Lord prohibits careless and profane oaths. Matt 5:34-36. Various formularies were
employed for oaths, such as: 'As the Lord liveth," 1 Sam 14:39; "Would God," Num 14:2; "As the Lord liveth, and as thy soul liveth." 2 Kgs 2:2, etc. From our Lord's prohibition of profane and careless oaths, we learn that oaths were taken by the more common things, such as the throne of God, Jerusalem, the earth, etc., Matt 5:34, sqq., and the temple, the gold of the temple, and the altar. Matt 23:16-22. As to-day the elevation of the right hand
is associated with taking an oath in our courts, so amongst the Hebrews oaths were frequently accompanied with peculiar ceremonies. As far back as Abraham's time lifting the hand was practised in this connection, Gen 14:22; Deut 32:40, etc., as also placing the hand under the thigh of another. Gen 24:2; Gen 47:29. In the O.T. the oath is taken as a ratification of agreements between the most diverse parties. The king or ruler takes an oath,
solemnly pledging himself to perform a promisee. 2 Kgs 25:24; Matt 14:7; the subject to his sovereign, Eccl 8:2; the governor exacts the oath from the priests, Neh 5:12; the master from his servant. Gen 24:2; the patriarch from his people. Gen 50:25, etc. Our Lord's prohibition of profane and careless swearing, Matt 5:34. has been understood by some - as the Friends - to exclude all oaths whatever. No doubt, should the spirit of Christ completely
pervade the world, the simple asseverations "Yea" and "Nay" would be all sufficient. The most solemn oath that a Mohammedan can make is, "By the beard of Mohammed."