We must also take into account the spirit of hostility which their religion fosters against the infidel--against, that is, all who do not accept the laws of the Prophet. "The sword," says Mohammed, "is the key of heaven and of hell; a drop of blood shed in the cause of God, a night spent in arms, is of more avail than two months of fasting or prayer: whosoever falls in battle, his sins are forgiven: at the day of judgment his wounds shall be resplendent as vermilion and odoriferous as musk; and the loss of his limbs shall be supplied by the wings of angels and cherubim." Such a declaration could not but fire the enthusiasm of the Arab, and whet their swords against the enemies of Islam. The leading features of his character have been discriminated by Gibbon with his usual sagacity, and described with his wonted stateliness of language. "In private life," he says,[77] "every man, at least every family, is the judge and avenger of his own cause. The nice sensibility of honour, which weighs the insult rather than the injury, sheds its deadly venom on the quarrels of the Arabs; the honour of their women, and their _beards_, is most easily wounded; an indecent action, a contemptuous word, can be expiated only by the blood of the offender; and such is their patient inveteracy, that they expect whole months and years the opportunity of revenge. A fine or compensation for murder is familiar to the barbarians of every age; but with the Arabs the kinsmen of the dead are at liberty to accept the atonement, or to exercise with their own hands the law of retaliation. Their refined malice refuses even the head of the murderer, substitutes an innocent for the guilty person, and transfers the penalty to the best and most considerable of the race by whom they have been injured. If he falls by their hands, they are exposed in their turn to the danger of reprisals, the interest and principal of the bloody debt are accumulated; the individuals of either family lead a life of malice and suspicion, and fifty years may sometimes elapse before the account of vengeance be finally settled. This sanguinary spirit, ignorant of pity or forgiveness, has been moderated, however, by the maxims of honour, which require in every private encounter some decent equality of age and strength, of numbers and weapons....