 The majority of <unk> believe they are one of the modern day descendants of Muhammad , and that they are therefore the descendants of Ishmael and his second son Qedar . Abu <unk> <unk> al @-@ <unk> ( 676 – 743 CE ) wrote that his father Ali ibn <unk> informed him that Mohammed had said : " The first whose tongue spoke in clear Arabic was Ishmael , when he was fourteen years old . " <unk> Ibn Muhammad al @-@ <unk> ( 737 – 819 CE ) established a genealogical link between Ishmael and Mohammed using writings that drew on biblical and <unk> sources , and the ancient oral traditions of the Arabs . His book , <unk> al @-@ <unk> ( " The <unk> of <unk> " ) , seems to <unk> that the people known as " Arabs " are all descendants of Ishmael . Ibn <unk> ( <unk> – <unk> ) writes , " All the Arabs of the <unk> are descendants of Nebaioth and Qedar . " Medieval Jewish sources also usually identified Qedar with Arabs and / or Muslims . According to author and scholar <unk> <unk> , Western scholars viewed this kind of " genealogical <unk> " with suspicion , seeing it as , 
