The Prophet ﷺ said, "A woman should not travel except with a Dhu-Mahram (her husband or a man with whom that woman cannot marry at all according to the Islamic Jurisprudence), and no man may visit her except in the presence of a Dhu-Mahram." A man got up and said, "O Messenger of Allah ﷺ! I intend to go to such and such an army and my wife wants to perform Hajj." The Prophet ﷺ said (to him), "Go along with her (to Hajj).  

قَالَ النَّبِيُّ ﷺ لاَ تُسَافِرِ الْمَرْأَةُ إِلاَّ مَعَ ذِي مَحْرَمٍ وَلاَ يَدْخُلُ عَلَيْهَا رَجُلٌ إِلاَّ وَمَعَهَا مَحْرَمٌ فَقَالَ رَجُلٌ يَا رَسُولَ اللَّهِ إِنِّي أُرِيدُ أَنْ أَخْرُجَ فِي جَيْشِ كَذَا وَكَذَا وَامْرَأَتِي تُرِيدُ الْحَجَّ فَقَالَ اخْرُجْ مَعَهَا  

I heard Messenger of Allah ﷺ delivering a sermon and making this observation:" No person should be alone with a woman except when there is a Mahram with her, and the woman should not undertake journey except with a Mahram." A person stood up and said: Messenger of Allah, my wife has set out for pilgrimage, whereas I am enlisted to fight in such and such battle, whereupon he said:" You go and perform Hajj with your wife."  

سَمِعْتُ النَّبِيَّ ﷺ يَخْطُبُ يَقُولُ لاَ يَخْلُوَنَّ رَجُلٌ بِامْرَأَةٍ إِلاَّ وَمَعَهَا ذُو مَحْرَمٍ وَلاَ تُسَافِرِ الْمَرْأَةُ إِلاَّ مَعَ ذِي مَحْرَمٍ فَقَامَ رَجُلٌ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّ امْرَأَتِي خَرَجَتْ حَاجَّةً وَإِنِّي اكْتُتِبْتُ فِي غَزْوَةِ كَذَا وَكَذَا قَالَ انْطَلِقْ فَحُجَّ مَعَ امْرَأَتِكَ  

"لا تُسَافِرِ المَرْأةُ إِلا مَعَ ذِي مَحْرَمٍ، وَلَا يَدْخُلُ عَلَيهَا رَجُلٌ إِلا وَمَعَهَا ذُو مَحْرَمٍ".  

"لَا يَخْلُوَنَّ رَجُلٌ بِامْرَأَةٍ إلا وَمَعَهَا ذُو مَحْرَمٍ، وَلَا تُسَافِر امْرَأَةٌ إلا مَحْرَمٍ، وَلَا يَدْخُل عَليهَا رَجُلٌ إلا مَعَ مَحْرَمٍ".