Musnad Abu Ya'la al-Mawsili 107:18

Harun narrated to us, Abdullah bin Wahb narrated to us, Amr informed us that Hisham bin Abi Ruqayyah narrated to him, saying: I heard Maslamah bin Mukhallad while he was standing on the pulpit delivering a sermon, and he was saying: "O people, do you not have enough in wool and linen to suffice you instead of silk? And here is a man among you who reports from the Messenger of Allah, may Allah bless him and grant him peace. Stand up, O Uqbah." So Uqbah bin Amir stood up, and I was listening, and he said: "I heard the Messenger of Allah, may Allah bless him and grant him peace, say: 'Whoever lies about me intentionally, let him take his seat in the Fire.' And I bear witness that I heard him say: 'Whoever wears silk in this world, he is forbidden from wearing it in the Hereafter.'"