A group came to Ali at ar-Rahbah and said, "Peace be upon you, our master."Ali replied, "How can I be your master when you are an Arab people?"They said, "We heard the Messenger of Allah ﷺ say on the Day of Ghadir Khumm, 'Whoever I am his master, this one is his master.'"Riyah said, When they left, I followed them and asked, "Who are these men?"They replied, "A group from the Ansar, among them Abu Ayub al-Ansari."
حدثنا يحيى بن آدم حدثنا حنش بن الحارث بن لقيط النخعي الأشجعي
جاء رهط إلى علي بالرحبة فقالوا السلام عليك يا مولانا قال كيف أكون مولاكم وأنتم قوم عرب قالوا سمعنا رسول الله ﷺ يوم غدير خم يقول من كنت مولاه فإن هذا مولاه قال رياح فلما مضوا تبعتهم فسألت من هؤلاء قالوا نفر من الأنصار فيهم أبو أيوب الأنصاري
Its chain of transmission is sahih. Hanash bin Harith bin Laqit Nakhai is trustworthy, and his hadith appears in Bukhari's Adab, while Rabah bin Harith is trustworthy, one of the senior successors, and the hadith has appeared previously at 23001 and 22841.