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Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
nasai-kubra:9556 – Aḥmad b. Sulaymān > ʿUbaydullāh b. Mūsá > Isrāʾīl > Abū Ḥaṣīn > Ibrāhīm > Sūwayd b. Ghafalah > ʿUmar

He did not allow the wearing of silk except (something) the width of four fingers. (Using translation from Nasāʾī 5313)  

الكبرى للنسائي:٩٥٥٦ – وَأَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ قَالَ حَدَّثَنَا عُبَيْدُ اللهِ بْنُ مُوسَى قَالَ أَخْبَرَنَا إِسْرَائِيلُ عَنْ أَبِي حَصِينٍ عَنْ إِبْرَاهِيمَ عَنْ سُوَيْدِ بْنِ غَفَلَةَ عَنْ عُمَرَ

«أَنَّهُ لَمْ يُرَخِّصْ فِي الدِّيبَاجِ إِلَّا مَوْضِعَ أَرْبَعَةِ أَصَابِعَ»  

See similar narrations below:

Collected by Nasāʾī
nasai:5313 – [Chain 1] ʿAbd al-Ḥamīd b. Muḥammad > Makhlad > Misʿar > And Barah > al-Shaʿbī > Sūwayd b. Ghafalah [Chain 2] Aḥmad b. Sulaymān > ʿUbaydullāh > Isrāʾīl > Abū Ḥaṣīn > Ibrāhīm > Sūwayd b. Ghafalah > ʿUmar

He did not allow the wearing of silk except (something) the width of four fingers.  

النسائي:٥٣١٣ – أَخْبَرَنَا عَبْدُ الْحَمِيدِ بْنُ مُحَمَّدٍ قَالَ حَدَّثَنَا مَخْلَدٌ قَالَ حَدَّثَنَا مِسْعَرٌ عَنْ وَبَرَةَ عَنِ الشَّعْبِيِّ عَنْ سُوَيْدِ بْنِ غَفَلَةَ ح وَأَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ قَالَ حَدَّثَنَا عُبَيْدُ اللَّهِ قَالَ حَدَّثَنَا إِسْرَائِيلُ عَنْ أَبِي حَصِينٍ عَنْ إِبْرَاهِيمَ عَنْ سُوَيْدِ بْنِ غَفَلَةَ عَنْ عُمَرَ

أَنَّهُ لَمْ يُرَخِّصْ فِي الدِّيبَاجِ إِلاَّ مَوْضِعَ أَرْبَعِ أَصَابِعَ