If a man has enlisted himself in the army and then his wife goes out for Hajj
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ أَبِي مَعْبَدٍ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ أَنَّهُ سَمِعَ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " لاَ يَخْلُوَنَّ رَجُلٌ بِامْرَأَةٍ، وَلاَ تُسَافِرَنَّ امْرَأَةٌ إِلاَّ وَمَعَهَا مَحْرَمٌ ". فَقَامَ رَجُلٌ فَقَالَ يَا رَسُولَ اللَّهِ، اكْتُتِبْتُ فِي غَزْوَةِ كَذَا وَكَذَا، وَخَرَجَتِ امْرَأَتِي حَاجَّةً. قَالَ " اذْهَبْ فَحُجَّ مَعَ امْرَأَتِكَ ".
Narrated Ibn `Abbas: That he heard the Prophet (ﷺ) saying, "It is not permissible for a man to be alone with a woman, and no lady should travel except with a Muhram (i.e. her husband or a person whom she cannot marry in any case for ever; e.g. her father, brother, etc.)." Then a man got up and said, "O Allah's Messenger! I have enlisted in the army for such-and-such Ghazwa and my wife is proceeding for Hajj." Allah's Messenger (ﷺ) said, "Go, and perform the Hajj with your wife."