Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) says: We were praying with the Messenger of Allah (peace and blessings be upon him), when suddenly he left while we were in the standing position. When he returned, drops of water were dripping from his head. Then he led us in prayer and (after finishing) said: When I stood for prayer, I remembered that I was in a state of janabah and had not performed ghusl. (In the future, remember that) if any of you feels a sound in his stomach or experiences what happened to me, then he should leave, and after fulfilling his need or performing ghusl, he should return to his prayer.