It is narrated from Ya'qub bin Ja'far bin Sulayman that he said: I heard my father say: I went in to Abu Ja'far al-Mansur and saw that he had a jummah (hair reaching the earlobes or the shoulders), and I began to gaze at its beauty. Abu Ja'far al-Mansur said: "My father Muhammad bin Ali also had a jummah, and he told me that his father Ali bin Abdullah also had a jummah, and he told me that his father Abdullah bin Abbas also had a jummah, and Ibn Abbas (may Allah be pleased with them both) told me that the Prophet (peace and blessings be upon him) also had a jummah which reached halfway down his ears." Ibn Abbas (may Allah be pleased with them both) said: "Abbas bin Abd al-Muttalib also had a jummah, Abd al-Muttalib also had a jummah, and Hashim bin Abd Manaf also had a jummah." Ya'qub bin Ja'far says: I said to my father: "I am amazed at its beauty." He said: "That is the light of the caliphate." Then (Abu Ja'far al-Mansur) said: My father narrated to me from his father, from his grandfather, that he said: "Indeed, when Allah Almighty intends to create someone for the caliphate, He passes His hand (of power) over his forelock, and then no eye falls upon him except that it loves him." All the narrators of this hadith, from first to last, are Hashimis well known for the nobility of their lineage.