Hadith 365

It was narrated from Suwaid bin Ghafalah that `Umar addressed the people in al-Jabiyah and said: The Messenger of Allah () forbade wearing silk except the width of two fingers or three or four - and he gestured with his hand.

حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنِ الشَّعْبِيِّ، عَنْ سُوَيْدِ بْنِ غَفَلَةَ، أَنَّ عُمَرَ، رَضِيَ اللَّهُ عَنْهُ خَطَبَ النَّاسَ بِالْجَابِيَةِ فَقَالَ نَهَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنْ لُبْسِ الْحَرِيرِ إِلَّا مَوْضِعَ أُصْبُعَيْنِ أَوْ ثَلَاثَةٍ أَوْ أَرْبَعَةٍ وَأَشَارَ بِكَفِّهِ‏.‏

Reference: 5303440
In-book reference: Book 2, Hadith 365
Hadith 365 - Musnad `Umar b. al-Khattab (ra) - Musnad Ahmad - Sunnah.com