Sahih Muslim 1341
Sahih Muslim · Book 15: The Book of Pilgrimage · A woman travelling with a Mahram for Hajj and other purposes
Ibn Juraij narrated this hadith with the same chain of transmitters, but he made no mention of it:
وَحَدَّثَنَا ابْنُ أَبِي عُمَرَ ، حَدَّثَنَا هِشَامٌ، - يَعْنِي ابْنَ سُلَيْمَانَ - الْمَخْزُومِيُّ عَنِ ابْنِ، جُرَيْجٍ بِهَذَا الإِسْنَادِ نَحْوَهُ وَلَمْ يَذْكُرْ " لاَ يَخْلُوَنَّ رَجُلٌ بِامْرَأَةٍ إِلاَّ وَمَعَهَا ذُو مَحْرَمٍ " .
" No person (man) should be alone with a woman except when there is a Mahram with her."