Sahih al-Bukhari 669
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · Can the Imam offer the Salat (prayer) with only those who are present (for the prayer)? And can be deliver a Khutba (religious talk) on Friday if it is raining?
Narrated Abu Sa`id Al-Khudri:
حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ ، قَالَ حَدَّثَنَا هِشَامٌ ، عَنْ يَحْيَى ، عَنْ أَبِي سَلَمَةَ ، قَالَ سَأَلْتُ أَبَا سَعِيدٍ الْخُدْرِيَّ فَقَالَ جَاءَتْ سَحَابَةٌ فَمَطَرَتْ حَتَّى سَالَ السَّقْفُ، وَكَانَ مِنْ جَرِيدِ النَّخْلِ، فَأُقِيمَتِ الصَّلاَةُ، فَرَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَسْجُدُ فِي الْمَاءِ وَالطِّينِ، حَتَّى رَأَيْتُ أَثَرَ الطِّينِ فِي جَبْهَتِهِ.
A cloud came and it rained till the roof started leaking and in those days the roof used to be of the branches of date-palms. Iqama was pronounced and I saw Allah's Messenger (ﷺ)s prostrating in water and mud and even I saw the mark of mud on his forehead.