It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both), he says that the Messenger of Allah (peace and blessings be upon him) came out from the toilet, and food was presented to him. The noble Companions (may Allah be pleased with them all) began to say: "Shall we not bring water for you to perform ablution (so that you may perform wudu)?" The Messenger of Allah (peace and blessings be upon him) said: "I have been commanded to perform ablution only when I stand for prayer."