Musnad Ahmad 435:6

'Affan narrated to us, he said: Hammam narrated to us, he said: Qatadah narrated to us, from Abu Shaykh al-Huna'i, who said: I was among a gathering of the companions of the Messenger of Allah, peace and blessings of Allah be upon him, with Mu'awiyah. Mu'awiyah said: "I adjure you by Allah, do you know that the Messenger of Allah, peace and blessings of Allah be upon him, forbade the wearing of silk?" They said: "By Allah, yes." He said: "And I bear witness." He said: "I adjure you by Allah, do you know that the Messenger of Allah, peace and blessings of Allah be upon him, forbade the wearing of gold, except for what is cut?" They said: "By Allah, yes." He said: "And I bear witness." He said: "I adjure you by Allah, do you know that the Messenger of Allah, peace and blessings of Allah be upon him, forbade riding on leopard skins?" They said: "By Allah, yes." He said: "And I bear witness." He said: "I adjure you by Allah, do you know that the Messenger of Allah, peace and blessings of Allah be upon him, forbade drinking from silver vessels?" They said: "By Allah, yes." He said: "And I bear witness." He said: "I adjure you by Allah, do you know that the Messenger of Allah, peace and blessings of Allah be upon him, forbade combining Hajj and 'Umrah?" They said: "As for this, no." He said: "As for it, it is with them."