Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said that the Prophet (peace and blessings be upon him), on the morning of Muzdalifah, would order his women and his family members "to set off at the very beginning of dawn while it was still dark, and not to stone before morning."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9567