In one narration the wording is: "I am Yemeni, and Hadramawt is better than Banu al-Harith, and I will not care if both tribes perish, for rule and kingship belong to Allah Almighty alone."
Ahmad recorded it both muttasil (connected) and mursal, and al-Tabarani also recorded it; he named the omitted narrator as Busr bin Ubaydullah. The narrators of all these narrations are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16548