Musnad Ahmad

It is narrated from Abdullah, who was the freed slave of Hazrat Asma, that once Hazrat Asma camped near the house of Muzdalifah and asked, "Son, has the moon set?" It was the night of Muzdalifah and she was praying. I said, "Not yet." She continued to pray for a while longer, then asked, "Son, has the moon disappeared?" By that time, the moon had set, so I said, "Yes!" She said, "Then depart." So we set out from there, and upon reaching Mina, performed the stoning of Jamrah Aqabah, and after reaching our tent, offered the Fajr prayer. I said to her, "We left Muzdalifah while it was still dark." She replied, "Not at all, son. The Prophet (peace be upon him) has given permission for women to depart early."