Abu Dawud Book 4, Hadith Number 2025.

Narated By Uthman ibn Talhah al-Hajabi : Al-Aslamiyyah said: I said to Uthman ibn Talhah al-Hajabi): What did the Apostle of Allah (PBUH) say to you when he called you? He said: (The Prophet said:) I forgot to order you to cover the two horns (of the lamb), for it is not advisable that there should be anything in the House (the Ka’bah) which diverts the attention of the man at prayer. Ibn as-Sarh said: The name of my maternal uncle is Musafi’ ibn Shaybah.