Sahih Bukhari Volume 8, Book 78, Hadith 6082

حَدَّثَنَا مُحَمَّدُ بْنُ سَلاَمٍ، أَخْبَرَنَا عَبْدُ الْوَهَّابِ، عَنْ خَالِدٍ الْحَذَّاءِ، عَنْ أَنَسِ بْنِ سِيرِينَ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم زَارَ أَهْلَ بَيْتٍ فِي الأَنْصَارِ فَطَعِمَ عِنْدَهُمْ طَعَامًا، فَلَمَّا أَرَادَ أَنْ يَخْرُجَ أَمَرَ بِمَكَانٍ مِنَ الْبَيْتِ، فَنُضِحَ لَهُ عَلَى بِسَاطٍ، فَصَلَّى عَلَيْهِ، وَدَعَا لَهُمْ‏

Narrated By Anas bin Malik : Allah's Apostle visited a household among the Ansars, and he took a meal with them. When he intended to leave, he asked for a place in that house for him, to pray so a mat sprinkled with water was put and he offered prayer over it, and invoked for Allah's Blessing upon them (his hosts).