Mukhtasar Muslim

Abu Uthman says that Syedna Umar (may Allah be pleased with him) wrote to us while we were in Azerbaijan (a country in Iran): "O Utbah bin Farqad, the wealth that is with you is neither earned by you, nor by your father, nor by your mother. So let the Muslims enjoy it in their places just as you enjoy it in your place (i.e., deliver it to them without them asking). And avoid living luxuriously, and avoid the ways of the polytheists, and also avoid wearing silk clothes—except this much." And the Messenger of Allah (peace and blessings be upon him) raised his middle and index fingers and joined them together (i.e., if there is a border of two fingers' width, it is permissible). Zuhair said to Asim, "This is what is in the book," and Zuhair raised both his fingers.

It is narrated from Suwaid bin Ghaflah that when Sayyiduna Umar bin Khattab (may Allah be pleased with him) delivered a sermon at (the place of) Jabiyah, he said that the Messenger of Allah (peace and blessings of Allah be upon him) forbade wearing silk (silken cloth), except (that) it be equal to two fingers, or three, or four fingers (in width).