Abdullah bin Abbas (may Allah be pleased with them) narrates: I heard the Prophet (peace be upon him) saying: "No man should ever be alone with a woman unless she is accompanied by a mahram." A man stood up and said: "O Messenger of Allah (peace be upon you)! My name has been registered for such-and-such battle, while my wife wants to go for Hajj." The Prophet (peace be upon him) said: "Go and perform Hajj with your wife."