Hugh Nibley
"…the oath is the one thing that is most sacred and inviolable among the desert people and their descendants: 'Hardly will an Arab break his oath, even if his life be in jeopardy,' for 'there is nothing stronger, and nothing more sacred than the oath among the nomads,' and even the city Arabs, if it be exacted under special conditions. 'The taking of an oath is a holy thing with the Bedouins, says one authority, 'Wo to him who swears falsely; his social standing will be damaged and his reputation ruined. No one will receive his testimony, and he must also pay a money fine.'
"But not every oath will do. To be most binding and solemn an oath should be by the life of something, even if it be but a blade of grass. The only oath more awful than that 'by my life' or (less commonly) 'by the life of my head,' is the wa hayat Allah 'by the life of God,' or 'as the Lord Liveth,' the exact Arabic equivalent of the ancient Hebrew hai Elohim. ...
"So we see that the only way that Nephi could possibly have pacified the struggling Zoram in an instant was to utter the one oath that no man would dream of breaking, the most solemn of all oaths to the Semite: 'As the Lord liveth, and as I live!'"(An Approach to the Book of Mormon, p.103-5)