Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) delivered a sermon: "No woman should travel without a mahram." A man stood up and said: "I have been enlisted for a military expedition, and I wanted to take my wife for Hajj." the Prophet (peace and blessings be upon him) said: "Perform Hajj with your wife."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12152