It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Indeed, Allah, the Mighty and Majestic, turned me to face Syria and turned my back towards Yemen, and He said to me: 'O Muhammad, I have made what is in front of you spoils and provision, and what is behind your back reinforcement. Islam will keep on increasing, and shirk and its people will keep on decreasing, until two women travel (alone) without fearing any injustice.'"
Then he said: "By the One in whose hand is my soul, the days and nights will not pass until this religion reaches as far as (the light of) this star."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7611