Musnad Ahmad 658:77

Yahya narrated to us, from Sufyan, who said: Abu Ishaq narrated to me, saying: I heard al-Bara’ saying: A silk garment was brought to the Prophet, may Allah bless him and grant him peace, and they began to marvel at its beauty and its softness. He said: "The handkerchiefs of Sa'd ibn Mu'adh in Paradise are better, or finer, than this."