The caliph Mu'awiya I appointed time oversee fiscal affairs in the vast province of Khurasan in 675 or 676, but he died on his way there.
[2] Along with his full brothers Isma'il and Yahya, Ishaq settled in Kufa and enjoyed the favor of the Umayyad caliphs who came to rule Iraq from 661.
[2][3] He and Isma'il were among those who testified against a prominent advocate of Ali's family, Hujr ibn Adi, who was executed in 671 by the Umayyad caliph Mu'awiya I (r. 661–680).
[6][7][8] In another account Ishaq was appointed to the same role alongside Sa'id ibn Uthman, who served as governor in 676.
[9] Ishaq married Umm Unas, a daughter of Abu Musa al-Ash'ari, who had served as governor of Kufa.