Musnad Ahmad 32:501

Hisham ibn Sa'id al-Taliqani narrated to us, Abu 'Awanah narrated to us, from 'Abd al-Rahman ibn al-Asamm, from Anas ibn Malik, who said: The Messenger of Allah (peace and blessings of Allah be upon him) sent a silk tunic (jubbah) to 'Umar. He said: So 'Umar met the Messenger of Allah (peace and blessings of Allah be upon him) and said: "You sent me a silk tunic, and you have said about it what you said." He said: "I did not send it to you for you to wear it; I only sent it to you for you to sell it or benefit from it."