Samaak Hanafi (may Allah have mercy on him) says that once I heard Sayyiduna Ibn Umar (may Allah be pleased with them both) saying that the Prophet (peace and blessings of Allah be upon him) prayed inside the House of Allah (the Ka'bah), but now you will go to a person and hear his words, who will deny this. He meant Sayyiduna Ibn Abbas (may Allah be pleased with him), who was sitting nearby.