Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: The Prophet (peace and blessings be upon him) would come to us, the young boys of Banu Abd al-Muttalib, mount us on our donkeys and pat our thighs, then he would say: "Do not stone the Jamrah before the sun has risen." And I do not think that anyone stoned before the sun had risen.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9565