Allah`s prophets always had the most pure family lineage. Before Hadhrat Abu Sufyaan accepted Islaam, he was asked by the Caesar of Rome; how is the Family Lineage of the Prophet Muhammad? Abu Sufyaan replied:
هو فينا ذو نسب
He is of a Good Lineage. [Bukhari]1
On hearing this Caesar replied:
و كذلك الرسل تبعث في نسب قومها
Prophets are always sent into noble families. [Bukhari]1