It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) visited a household of the Ansar and ate food with them. When he was about to leave, he instructed that a certain place in the house be cleaned. So, water was sprinkled on a mat and it was spread out for him. The Prophet (peace and blessings of Allah be upon him) prayed on it and supplicated for them.