It is narrated from Sayyidah Aishah (may Allah be pleased with her) that when she set off on the morning after Muzdalifah, and reached the middle of the valley of Muhassir, she would say to me: Urge the mount on (make it hurry) and make it rise. (Umm Alqamah) said: One day I urged the mount on, and the mount fell on its forelegs while the howdah was on it. Then I urged it on a second time, and Allah raised it up, and it did her no harm at all. She would keep her mount raised (moving fast) until she crossed the valley of Muhassir and entered the valley (middle) of Mina.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9529