Volume Two: 2:192: Ibn 'Umar: The Prophet said, A woman should not travel for more than three days ...

Hadith 2:192

Narrated Ibn 'Umar:

The Prophet said, "A woman should not travel for more than three days except with a Dhi-Mahram (i.e. a male with whom she cannot marry at all, e.g. her brother, father, grandfather, etc.) or her own husband.)"