 Abu Ja‛far Yusuf ibn Hasday is also the recipient of a letter from Avempace in which he refers to the astronomer az-Zarqalluh, Azarquiel (d. ca. 1000), and also writes about his own order of  learning.[6]  Abu Ja‛far (d. 1123) was the great-great-grandson of the famous Jewish scholar and statesman Hasday Ibn Shaprut (ca. 910–ca. 970; Stroumsa 2016). Ibn Abi Usaybi‛a includes in Abu Ja‛far’s biography his history of  physicians,[7]  and reports his friendship with Avempace. Sa‛id Ibn Sa‛id gives a biography of probably his grandfather, Abu l-Fadl Hasday ibn Yusuf (fl. 485/1092), “of the city of Saragossa and of the Jewish nobility in al-Andalus” who was first to read Aristotle’s Physics and De caelo in  al-Andalus.[8]