Among the popular beliefs of Islam--and it is one common to every sect, Shiite and Abadite, as well as Sunite--is this one, that in the latter days of the world, when the power of God's worshippers shall have grown weak and their faith corrupted, a leader shall arise who shall restore the fortunes of the true believers. He shall begin by purging the earth of injustice, fighting against oppressors wherever he shall find them, Mohammedan as well as Infidel, and he shall teach the people a perfect law which they shall have forgotten, and he shall reign over Islam in place of their Khalifeh, being called the Mohdy, or guide. To this some add that he will arise of a sudden in some distant corner of the earth, and that he will march towards Mecca, and that everywhere the blood of Moslems shall be shed like water, and that he shall enter Mecca when the streets shall run with blood. In support of this coming of the Mohdy many traditions exist which are held to be authentic by the Ulema. Thus it is related on the authority of Abdallah ibn Messaoud that he heard the Prophet say, "When there shall remain but one day of the days of the earth, God shall prolong that day, and shall send forth from my house a man bearing my name and the name of my father (Mohammed ibn Abdallah), and he shall purify the earth from injustice and fill it with that which is right." The same was heard also by Ali Ibn Abu Taleb, the Prophet's son-in-law, and by Hadhifat Ibn el Yaman, who relates that this prophecy was delivered by Mohammed one Friday at the Khotbah, or sermon, in Medina. Salman el Faris, another witness, declares that he afterwards approached the Prophet and stood before him and asked him, "From which of thy descendants, O Apostle of God, shall the Mohdy be?" And the Prophet answered, stretching his hand towards his grandson Huseyn, "From this child shall he come." Besides this general belief, which, though not a positive dogma of their faith, is common to all Mussulmans, the Shiites, always prone to exaggerate and embellish, maintain that the Mohdy's duty is not limited to teaching, guiding, and purifying the law, but also that he shall revenge the blood unjustly shed of the Imams; and they cite in support of this a tradition of Ali ibn Abu Taleb, who thus addressed his son, Huseyn, the same who was afterwards martyred at Kerbela, "I swear to thee, O my son," he said, "I swear by my soul, and by my offspring, and by Kerbela, and by its temple, that the day shall come in which our beards shall be dyed with blood. And I swear that afterwards God shall raise up a man, the Mohdy, who shall stand in our place, the lord of mankind. He it is who shall avenge us, nay, he shall avenge thy blood also, O Huseyn. Therefore have patience. For the blood of one man he shall shed the blood of a thousand; and he will not spare them who have helped our enemies."