A woman travelling with a Mahram for Hajj and other purposes Sahih Muslim 1341 c
Arabic hadith text
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
Translation
Ibn Juraij narrated this hadith with the same chain of transmitters, but he made no mention of it
" No person (man) should be alone with a woman except when there is a Mahram with her."