"My grandmother Mutalikah invited Allah's Messenger to a meal that she prepared. He ate from it, then said: 'Stand so tht we may lead you in prayer.'" He said: "I got a Hasir of our which had become dark because of prolonged use, so I washed it with water. Allah's Messenger stood on it, and the orphan and I aligned behind him and the only lady stood behind us. He (Allah's Messenger) led us in two Rak'ah of prayer and then left."
Jami` at-Tirmidhi Book 2, Hadith 86