Mukhtasar Bukhari (Abridged) 1988 — Wearing or sitting on silk

It is narrated from Amir al-Mu'minin Umar bin Khattab (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) forbade silk clothing except to the extent—then the Prophet (peace be upon him) joined his index and middle fingers and showed (i.e., it is permissible up to the width of two fingers). By this, he meant the border or embroidery of the cloth.