I came to the Prophet ﷺ while he was inside a red leather tent, and I saw Bilal taking the remaining water of the ablution of the Prophet, and the people were taking of that water and rubbing it on their faces; and whoever could not get anything of it, would share the moisture of the hand of his companion (and then rub it on his face).  

أَتَيْتُ النَّبِيَّ ﷺ وَهْوَ فِي قُبَّةٍ حَمْرَاءَ مِنْ أَدَمٍ وَرَأَيْتُ بِلاَلاً أَخَذَ وَضُوءَ النَّبِيِّ ﷺ وَالنَّاسُ يَبْتَدِرُونَ الْوَضُوءَ فَمَنْ أَصَابَ مِنْهُ شَيْئًا تَمَسَّحَ بِهِ وَمَنْ لَمْ يُصِبْ مِنْهُ شَيْئًا أَخَذَ مِنْ بَلَلِ يَدِ صَاحِبِهِ  

The Prophet ﷺ called for the Ansar and gathered them in a leather tent.  

أَرْسَلَ النَّبِيُّ ﷺ إِلَى الأَنْصَارِ وَجَمَعَهُمْ فِي قُبَّةٍ مِنْ أَدَمٍ