Bahá'u'lláh had four paternal uncles. Among those to whom He taught the Faith of the Báb in Nur were these uncles. Two of them rejected the Cause of God and actively rose up against it. These were Shaykh Aziz'u'llah and Safi Quli Big. The other two, Mulla Zaynu'l-'Abidin and Karbila'i Zaman, became ardent believers. The former accompanied Bahá'u'lláh to the fortress of Shaykh Tabarsi, and when Bahá'u'lláh was bastinadoed in Amul, threw himself upon His feet and was beaten so much that he fainted.
(Adib Taherzadeh, The Revelation of Baha'u'llah vol. 2)