Of such importance is this mode of speech to Orientals that the Israelites thought of Jehovah Himself as making such affirmations. In the twenty-second chapter of Genesis we have the words, "By myself have I sworn, saith the {170} Lord." Further light is thrown on this point by the explanation given to the verse just quoted in the sixth chapter of the Epistle to the Hebrews, where it is said, "For when God made promise to Abraham, because he could swear by no greater, he swore by himself." I have no doubt that this thought of God swearing by himself sprang from the custom of Oriental aristocrats of sealing a vow, or solemnly affirming a statement, or an intention to do some daring deed, by saying, "I swear by my head"--an oath which, whenever I heard it in my youth, filled me with awe. Thus, also, in the sixty-second chapter of Isaiah we have the words, "The Lord hath sworn by his right hand, and by the arm of his strength." Among the Mohammedans, swearing "by the most high God" and "by the life of the Prophet" and "by the exalted Koran" in affirmation of almost every statement, is universal. The Christians swear by God, Christ, the Virgin, the Cross, the Saints, the repose of their dead, the Holy City, the Eucharist, {171} Heaven, great holidays, and many other names. A father swears by the life of a dear child, and sons of distinguished fathers swear by them. "By the life of my father, I am telling the truth," is a very common expression. The antiquity of this custom is made evident by the passage in the thirty-first chapter of Genesis and the fifty-third verse: "And Jacob sware by the fear of his father Isaac." However, the word "fear" does violence to the real meaning of the verse, which the Arabic version rescues by saying, "And Jacob swore by the _heybet_ [benignity, or beautiful dignity] of his father." He swore by that which he and others loved, and not feared, in his father. But what must seem to Americans utterly ridiculous is the Oriental habit of swearing by the mustache and the beard, which is, however, one phase of swearing by the head. To swear by one's mustache, or beard, means to pledge the integrity of one's manhood. "I swear by this," is said solemnly by a man with his hand upon his mustache. Swearing by the {172} beard is supposed to carry more weight because, as a rule, it is worn by the older men. To speak disrespectfully of one's mustache or beard, or to curse the beard of a person's father, is to invite serious trouble.