Sayf was a staunch advocate of the Umayads...
Sayf was a staunch advocate of the Umayads, who were known throughout history to be one of the worst enemies of Ahlul-Bayt, and as such, it was in his best interest to invent such stories to degrade the Shia. In his stories however he followed many other goals one of which was to cleverly elevate the status of his tribe over others by inventing some imaginary companions form his tribe.
However many Sunni scholars found numerous unjustifiable heresies in his reports which was not limited to the issue of Abdullah Ibn Saba, and consequently they abandoned his reports, and accuse him as a man of forgery and lies. Yet Sayf's works enjoyed the support of a minority of Sunnis to this date. Here, later on, I give the sayings of several leading Sunni scholars, who all confirmed that Sayf Ibn Umar was an untrustworthy person and his stories are void.
Ideological studies indicate that most of those who hate the Shi'ite school of thought (a lot of whom being the enemies of Islam anyway) justify their enmity on this obvious heresy which they would exploit to backup their attack on Shia. The approach which resembles the one adopted by Sayf Ibn Umar himself. The Origin of The Tale The tale of Abdullah Ibn Saba is over twelve centuries old. Historians and writers, one after the other recorded it, adding more and more to it.
With a glance at the chain of transmitters of this story, you will find the name of Sayf sitting in there. The following historians recorded directly from Sayf: (1) Tabari. (2) Dhahabi. He has also cited from Tabari(1). (3) Ibn Abi Bakir. He has also recorded from Ibn Athir(15), who has recorded from Tabari(1). (4) Ibn Asakir. The following have recorded indirectly from Sayf: (5) Nicholson from Tabari(1). (6) Encyclopedia of Islam from Tabari(1). (7) Van Floton from Tabari(1).
(8) Wellhauzen from Tabari(1). (9) Mirkhand from Tabari(1). (10) Ahmad Amin from Tabari(1), and from Wellhauzen(8). (11) Farid Wajdi from Tabari(1). (12) Hasan Ibrahim from Tabari(1). (13) Saeed Afghani from Tabari(1), and from Ibn Abi Bakir(3), Ibn Asakir(4), and Ibn Badran(21). (14) Ibn Khaldoon from Tabari(1). (15) Ibn Athir from Tabari(1). (16) Ibn Kathir from Tabari(1). (17) Donaldson from Nicholson(5), and from Encyclopedia(6). (18) Ghiath al-Din from Mirkhand(9).
(19) Abul Fida from Ibn Athir(15). (20) Rashid Ridha from Ibn Athir(15). (21) Ibn Badran from Ibn Asakir(4). (22) Bostani from Ibn Kathir(16).