While these authors throw some light on the subject that the sect in question derives its appellation from a historic person, they leave us entirely in the dark as to who that person was, as the Arab historians mention many prominent men who bore the name Yezid.
This obscurity regarding the person of the founder of the sect is made clear by one whose work is equally, if not more, authoritative than that of any other Mohammedan scholar on matters pertaining to religious and philosophical sects. This authority is Mohammed Aš-Šahrastani. He is the only Mohammedan writer that I could reach that, in a clear language, traces this most interesting sect to its founder.
“The Yezidis are the followers of Yezid bn Unaisa, who [said that he] kept friendship with the first Muhakkama before the Azariḳa, and he separated himself from those who followed after them with the exception of Al-Abaḍia, for with these he kept friendship. He believed that God would send an apostle from among the Persians and would reveal to him a book that is already written in heaven, and would reveal the whole (book) to him at one time,[115] and as a result he would leave the law of Mohammed, the Chosen One, may God bless and save him!—and follow the religion of the Sabians mentioned in the Koran. But these are not the Sabians who are found in Ḥaran and Wasit. But Yezid kept friendship with the people of the book who recognized the Chosen One as a prophet, even though they did not accept his (Mohammed’s) religion. And he said that the followers of the ordinances are among those who agree with him; but that others are hiding the truth and give companions to God and that every sin, small or great, is idolatry.”[116]
It is clear, then, that Aš-Šahrastani finds the religious origin of this interesting people in the person of Yezid bn Unaisa. He calls them his Aseḥab, i. e., his followers, a term by which he designates the relation between a sect and its originator. Al-Ḥaraṯiyah he describes as “Aseḥab al-Ḥareṯ,” and “Al Ḥafeziyah Aseḥab Hafez,” and so on. We are to understand, therefore, that to the knowledge of the writer, bn Unaisa is the founder of the Yezidi sect, which took its name from him.
Mohammed Aš-Šahrastani states also, in a logical way, the theological views of the head of the Yezidis. Yezid, he says, is on the positive side, in sympathy with the first Muḥakkamah before the Azariḳa. Now, the first Muhakkamah is an appellative applied to the Muslim schismatics called Al-Ḫawarij, because they disallowed the judgment of the Hakaman, i. e., the two judges, namely ‘Abd Mousa al-Aš-‘Aree and Am ibn-al-‘As; and said that judgment belongs only to God. And Al-Azariḳa were a heretical Muslim sect called Al-Ḫawarij or Ḥeroriyah, so named in relation to Nafi‘ ibn-Al-Azraḳ. They asserted that ‘Ali committed an act of infidelity by submitting his case to arbitration, and that the slaying of him by Ibn Muljama was just; and they declare that the companions (of the Prophet) were guilty of infidelity. Yezid moreover, is said to have been in sympathy with Al-Abaḍiyah, a sect founded by ‘Abd-Allah ibn Ibad, who taught that if a man commits a kabirah or great sin he is an infidel and not a believer.
It is evident, therefore, that according to this exposition the Yezid in question was one of Al-Ḫawarij, and their principle is expressly attributed to him: every sin, small or great, is idolatry. According to this it might be inferred that the Yezidis were originally a Ḫarijite sub-sect. They still hold to the Ḫarijite principle. (Cf. their position to the Ottoman Government, pp. 71-74). As we said some Mohammedan writers other than Ashahr-Astani also (pp. 118-119) regard them as apostate Moslems, Aš-Šahrastani himself classes them with the Moslem heretics. Now Al-Ḫawarij were the first to rebel against ‘Ali at Ḥaroora, a certain suburb of Al-Koofa, from which it is distant two miles. They are called also Al-Ḥeroriyah, because they first assembled there and accepted the doctrine that government belongs only to God. And one sect of Al-Ḫawarij was An-Nâṣibiyah who made it a matter of religious obligation to bear a violent hatred to ‘Ali. Such is the place of bn Unaisa among the Moslem heretics, but this is only one side of his religious system.[117]
There is another side to Yezid’s doctrine. He held that God would send an apostle from Persia, to whom he would reveal a book already written in heaven. This apostle was to be an opponent of the prophet of Islam in that he would leave Mohammed’s religion and follow that of the Ṣabians mentioned in the Koran. These are referred to by Mohammed, together with the Christians and the Jews, in three different places in the Book. One such reference is in Surah 2, 59: “They who believe as well as Jews, Christians and Sabeans, whoever believeth in God and in the Last Day, and do that which is right, shall have their reward with their Lord.”
Surah 5, 73, also:
“They who believe as well as Jews, Christians and Sabeans, whoever of them believe in God and the Last Day, and do what is right, on them shall no fear come; neither shall they be put to grief.”
And Surah 22, 17:
“They who believe as well as Jews, Sabeans and Christians and the Magians, and those who join gods with God, verily God shall decide between them on the Day of Resurrection.”
In these passages Mohammed seems to regard the Sabians of the Koran as believers in the true God and in the resurrection. And in Surah 22, 17, he seems to distinguish them from Magians and polytheists. Hence, we are to infer that the Apostle of whom Yezid bn Unaisa says that he will come from the land of the ´Ajam (Persian), will identify himself with the religion of the Ṣabians. This implies that he will believe in the true God and in the Day of Resurrection. But from some Arab writers we learn more of these Ṣabian beliefs than the Prophet of Islam has mentioned. According to some the Ṣabians were a sect of unbelievers who worshipped the stars secretly, and openly professed to be Christians. According to others, they were of the religion of Ṣabi, the son of Seth, the son of Adam; while others said they resembled the Christians, except that their ḳiblah was toward the South, from whence the wind blows. In the Kamûs it is said that they were of the religion of Noah. Al-Baiḍawi says that some assert that they were worshippers of angels, and that others say that they are the worshippers of stars. Al-Bertuni[48] calls the Manichaeans of Samarḳand Sabians. Bar Hebraeus[118] asserts that the religion of the Sabians is the same as that of the ancient Chaldeans. In commenting on Surah 2, 59, Zamaḫšari (Al-Keššaf) says that the name Ṣabian comes from a root meaning one who has departed from one religion to another religion, and that the Ṣabians were those who departed from Judaism and Christianity and worshipped angels. On this same verse, Šams Ad-Din Mohammed Al-Ḥarrani (Jami Al-Bijan fi Tafsir Al-Koran) says: “The Ṣabians, i. e., those who departed from one religion to another religion, stood between the Magians and the Jews and the Christians without having any revealed religion of their own. According to some they were people of the Book; according to others they were worshippers of angels; while others say, they believed in one God but followed no Prophet.” This same commentator on Surah 5, 73, says: “The Ṣabians were a Christian sect; some say that they were worshippers of angels; others assert that they worshipped God alone, but had no revealed religion.” On this same verse Zamaḫšari remarks, “The Ṣabians were those who departed from all religions.”