The author of Sistans book is unique in mentioning the lineage of Yaqub, saying: Yaqoub bin Al-Layth bin Modid bin Hatim bin Mahan bin Kikhsru bin Ardashir bin Qabbad bin Khusraw Abru Perwaz bin Hormuz bin Khusrawan bin Anushrawan bin Qabbad bin Fairouz bin Yazdgerd bin Bahram Jor ... On this basis, if we take this story, Jacob descends from a high Iranian origin related to the Sasanian kings, and it seems that Jacob and other rulers of Persia were creating the genealogies related to the Sasanian kings to justify their existence and rule at the time. In addition to that, the owner of the book Sistan raises the status of Jacob during this period as well. However, we understand from the books of translations and other historical sources that Jacob used to belong to a poor family of common people engaged in some simple work. It was mentioned that Jacob used to work in his youth with the work of zero (copper) for a wage of (15) fifteen dirhams per month. As for his brother Amr ibn al-Laith, he used to work as a carpenter and then a makar. Then they joined the volunteer corps. If we take this second story, Yaqoub and his brother Amra were of unknown parentage, and from a poor Persian family.