The tribe to which this young man boasted that he belonged was one of those that elected to remain Christian, while other tribes of Mesopotamia, such as the Banū Namir and the Banū Quḍāʻah, became Muslim. The Banū Taghlib had sent an embassy to the Prophet as early as the year A.H. 9. The heathen members of the deputation embraced Islam and he made a treaty with the Christians according to which they were to retain their old faith but were not to baptise their children. A condition so entirely at variance with the usual tolerant attitude of Muḥammad towards the Christian Arabs, who were allowed to choose between conversion to Islam and the payment of jizyah and never compelled to abandon their faith, has given rise to the conjecture that this condition was suggested by the Christian families of the Banū Taghlib themselves, out of motives of economy. [56] The long survival of Christianity in this tribe shows that this condition was certainly not observed. The caliph ʻUmar forbade any pressure to be put upon them, when they showed themselves unwilling to abandon their old faith and ordered that they should be left undisturbed in the practice of it, but that they were not to oppose the conversion of any member of their tribe to Islam nor baptise the children of such as became Muslims. [57] They were called upon to pay the jizyah [58] or tax imposed on the non-Muslim subjects, but they felt it to be humiliating to their pride to pay a tax that was levied in return for protection of life and property, and petitioned the caliph to be allowed to make the same kind of contribution as the Muslims did. So in lieu of the jizyah they paid a double Ṣadaqah or alms, [59]—which was a poor tax levied on the fields and cattle, etc., of the Muslims. [60] It especially irked the Muslims that any of the Arabs should remain true to the Christian faith. The majority of the Banū Tanūkh had become Muslim in the year A.H. 12, when with other Christian Arab tribes they submitted to Khālid b. al-Walīd, [61] but some of them appear to have remained true to their old faith for nearly a century and a half, since the caliph al-Mahdī (A.H. 158–169) is said to have seen a number of them who dwelt in the neighbourhood of Aleppo, and learning that they were Christians, in anger ordered them to accept Islam—which they did to the number of 5000, and one of them suffered martyrdom rather than apostatise. [62] But for the most part, details are lacking for any history of the disappearance of Christianity from among the Christian Arab tribes of Northern Arabia; they seem to have become absorbed in the surrounding Muslim community by an almost insensible process of “peaceful penetration”; had attempts been made to convert them by force when they first came under Muhammadan rule, it would not have been possible for Christians to have survived among them up to the times of the ʻAbbāsid caliphs. [63]