Mukhtasar Bukhari

Narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them) that he heard the Prophet Muhammad (peace and blessings be upon him) say: "No man should sit in seclusion with a woman, and no woman should travel except with a mahram (close male relative)." Then a man stood up and said, "O Messenger of Allah! My name has been registered for such-and-such battle, and my wife is going for Hajj." So the Prophet (peace and blessings be upon him) said: "Go and perform Hajj with your wife."