"You are warned, O servants of Allah! that we have to exact vengeance from such a tribe that has offered us such or such an insult. Shoe your horses. Supply yourselves with provisions for a fortnight. Forget not the wheat, the barley, the dried meat, and the butter. You must provide not only for your own wants, but also that you may be able to afford a generous hospitality to the horsemen of such and such tribes that are coming to our assistance. Command your prettiest women to hold themselves in readiness to accompany us, and to array themselves in their finest garments, and adorn their camels and litters to the utmost of their power. Do you yourselves also put on your handsomest dresses, for with us it is a matter of _nif_ [self-love]. Keep your arms in good condition. Supply yourselves with powder, and be assembled on such a day at such a spot. The horseman who owns a mare and does not come, the foot-soldier who possesses a gun and stays at home, shall be fined, the former twenty ewes and the latter ten." Every able-bodied man, though he should have to go on foot, is bound to join in the expedition. Before setting out, the chiefs confide the flocks, tents, and baggage of the tribe to the care of experienced veterans, who are likewise charged to exercise a sort of police supervision over this assembly of women, children, invalids, and shepherds. The enemy, on their part, likewise make their preparations. Warned by travellers, by friends, and even by relatives whom they claim in the opposite party, they hasten to write in all directions to assemble their allies. Their flocks, tents, and baggage they place in a secure spot, and then assign a rendez-vous to the horsemen with the least possible delay. To guard against a surprise, they select a position suitable for defence, and await whatever may happen. They have not long to wait. The tribe that has taken up arms to avenge itself is very soon on the march, for it has not lost a single moment. On the evening before their departure, all the auxiliary chiefs join those who have summoned them, and, in the presence of the marabouts, take the following oath on the sacred book of Sidi Abd-Allah:— "O friends! let us swear by the truth of the sacred book of Sidi Abd-Allah that we are brothers, that all our guns shall be as one, and that, in dying, we will all die by the same sabre. If you call us by day, we will come by day, and if you summon us by night, we will hasten to you by night."