Musannaf Ibn Abi Shayba 27:682

Waki’ narrated to us, from Sufyan, from Abu Ishaq, from Al-Bara’ ibn ‘Azib, who said: A garment of silk was gifted to the Prophet, may Allah bless him and grant him peace, and they began to marvel at its softness. The Messenger of Allah, may Allah bless him and grant him peace, said: "The handkerchiefs of Sa’d in Paradise are softer than this."