From Sahih Muslim (Hadith 3450):
Nabaih b. Wahb reported that Umar b. 'Ubaidullah b. Ma'mar intended to marry his son Talha with the daughter of Shaiba b. Jubair during the Pilgrimage. Aban b. Uthman was at that time the Amir of Pilgrims. So he ('Umar b. Ubaidullah) sent someone (as a messenger) to Aban saying:I intend to marry Talha b. 'Umar and I earnestly desire you to be present there (in this ceremony of marriage). Aban said to him: I find you a block-headed 'Iraqi. I heard 'Uthman b. 'Affan say that Allah's Messenger (ﷺ) said: A Muhrim should not marry
Reference: Muslim 3450