Malik related to me from Said ibn Abi Said al-Maqburi from Abu
Hurayra that the Messenger of Allah, may Allah bless him and grant him
peace, said, "It is not halal for a woman who believes in Allah and
the Last Day to travel the distance of a day and night without a man
who is her mahram."
Muwatta Malik Book 54, Hadith 38