While we were at Adharbijan, ʿUmar wrote to us: 'Messenger of Allah ﷺ forbade wearing silk except this much. Then the Prophet ﷺ approximated his two fingers (index and middle fingers) (to illustrate that) to us.' Zuhair (the sub-narrator) raised up his middle and index fingers.  

أَنَّ النَّبِيَّ ﷺ نَهَى عَنْ لُبْسِ الْحَرِيرِ إِلاَّ هَكَذَا وَصَفَّ لَنَا النَّبِيُّ ﷺ إِصْبَعَيْهِ وَرَفَعَ زُهَيْرٌ الْوُسْطَى وَالسَّبَّابَةَ  

[Machine] "Beware of wearing silk garments, as the Messenger of Allah ﷺ forbade wearing silk clothing except in this manner."  

«إِيَّاكُمْ وَلِبَاسَ الْحَرِيرِ فَإِنَّ رَسُولَ اللهِ ﷺ نَهَى عَنْ لِبَاسِ الْحَرِيرِ إِلَّا هَكَذَا وَرَفَعَ إِصْبَعَيْهِ السَّبَّابَةَ وَالْوُسْطَى»