He knew the Kureisch had instituted a policy of alliance with the surrounding tribes, and that now their plan would be to crush him by a ceaseless pressure from the east, united to the inevitable disaffection within the city as its inhabitants witnessed the decline of their leader's power. Watchfulness and severity were the only means of holding his position, and these two qualities he used with a tenacity which alone secured his ultimate success. The first threatenings came from the Beni Asad, a powerful tribe inhabiting the country directly east of Medina. Under their chief Tuleiha, they planned a raid against Mahomet. But his excellent system of espionage stood him, now as always, in good stead, so that he heard of their scheme before it was ripe, and despatched 150 men to frustrate it. The Beni Asad were wise enough to give up the attempt after Mahomet's men had found and plundered their camp. They dispersed for the time being, and the danger of an attack was averted. But scarcely had the expedition returned when news came of another gathering at Orna, between Mecca and Taif. Again Mahomet lost no time, but sent a force large enough to disperse them in a skirmish, in which the chief of the Lahyan tribe was killed. In the next month Mahomet sent six of his followers to Mecca, probably as spies, but they were not allowed to reach their goal in safety. At Raja they fell in with a party of the Beni Lahyan proceeding the same way. The men were armed, and Mahomet's followers were glad to accompany them, because of the additional security. At the oasis the party encamped for the night, and the Muslim prepared unsuspectingly for sleep. At dead of night they were surrounded by their professed friends, who were resolved on revenge for the murder of their chief. Four were killed, and two, Zeid and Khubeib, taken bound to Mecca, whose citizens gloated over their prey. Legends in plenty group themselves around these two figures--the first real martyrs for Islam, and one of the most profound testimonies to the love which Mahomet inspired in his followers is given traditionally in a few significant sentences dealing with the episode. The prisoners were kept a month before being led to the inevitable torture. Abu Sofian, the scoffer, came to Zeid as he was preparing to face his death. "Wouldst thou not, O Zeid," he asked, "that thou wert once more with thy family, and that Mahomet suffered in thy place?" "By Allah! I would not that Mahomet should suffer the smallest prick from a thorn; no, not even if by that means I could be safe once more among my kindred." Then the enemy of Islam marvelled at his words and said: "Never have I seen among men such love as Mahomet's followers bear towards him." And after that Zeid was put to death. Mahomet was powerless to retaliate, and was obliged to suffer from afar the murder of his fellow-believers.