Sahih Muslim 1500
The Book of Mosques and Places of Prayer
وَحَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، وَأَبُو الرَّبِيعِ، كِلاَهُمَا عَنْ عَبْدِ الْوَارِثِ، قَالَ شَيْبَانُ حَدَّثَنَا عَبْدُ الْوَارِثِ، عَنْ أَبِي التَّيَّاحِ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم أَحْسَنَ النَّاسِ خُلُقًا فَرُبَّمَا تَحْضُرُ الصَّلاَةُ وَهْوَ فِي بَيْتِنَا فَيَأْمُرُ بِالْبِسَاطِ الَّذِي تَحْتَهُ فَيُكْنَسُ ثُمَّ يُنْضَحُ ثُمَّ يَؤُمُّ رَسُولُ اللَّهِ صلى الله عليه وسلم وَنَقُومُ خَلْفَهُ فَيُصَلِّي بِنَا وَكَانَ بِسَاطُهُمْ مِنْ جَرِيدِ النَّخْلِ .
Anas b. Malik reported that the Messenger of Allah (ﷺ) wits the best among people in character. On occasions, the time of prayer would come while he was in our house. He would then order to spread the mat lying under him. That was dusted and then water was sprinkled over it. The Messenger of Allah (ﷺ) then led the prayer and we stood behind him, and that mat was made of the leaves of date-palm
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.