Musnad Ahmad 32:1548

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, who said: 'Asim ibn 'Umar ibn Qatadah narrated to me, from Anas ibn Malik, who said: I saw the *qaba'* (cloak) of Ukaydir when it was brought to the Messenger of Allah, may Allah bless him and grant him peace. The Muslims began touching it with their hands and marveling at it. The Messenger of Allah, may Allah bless him and grant him peace, said: "Do you marvel at this? By the One in Whose hand is the soul of Muhammad, the handkerchief of Sa'd ibn Mu'adh in Paradise is better than this."