Hadith 31-273

وَبِإِسْنادِهِ عَنْ عَلِيِ‏ عَلَيْهِ السَّلامُ قالَ: قالَ النَّبِيُ‏ صَلَّى اللهُ عَلَيْهِ وَآلِهِ: الأَئِمَّةُ مِن قُرَيْشٍ.

According to the same documentation, on the authority of Ali (a.s.), the Prophet (S) said, “The Imams (a.s.) are all going to be from the Quraysh (tribe).”