Musnad Ahmad 1025:1

Sufyan narrated to us, Mansur narrated to me, from his maternal uncle Musafi’, from Safiyyah bint Shaybah, the mother of Mansur, who said: A woman from Banu Sulaym, who had delivered most of the people of our house, informed me: The Messenger of Allah (ﷺ) sent for Uthman ibn Talhah. And he said once: She asked Uthman: "Why did the Prophet (ﷺ) call you?" He said: "I had seen the two horns of the ram when I entered the House (the Ka'bah), and I forgot to order you to cover them, so cover them. For it is not fitting that there should be anything in the House that distracts the one praying." Sufyan said: The two horns of the ram remained in the House until the House burned down, and they burned with it.