Sunan Ibn Majah 756
سنن ابن ماجه#756SahihIt was narrated that Anas bin Malik said:"One of my paternal uncles made some food for the Prophet and said to the Prophet: 'I would like you to eat and perform prayer in my house.' So he went to him, and in his house there was one of these Fahl. He ordered that a corner be swept and water sprinkled in it, then he performed prayer and we prayed with him.'" (Sahih)Abu 'Abdullah bin Majah said: A Fahl is a mat that has become black (through use)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 4:22