Yahya related to me from Malik that he had heard some of thepeople of knowledge saying, "The pebbles used for stoning the jamrasshould be like the stones used as slingshot."Malik said, "Ilike it better if they are a little larger than that."Yahyarelated to me from Malik from Nafi that Abdullah ibn Umar used to say,"Someone who is at Mina when the sun sets in the middle of the days oftashriq must not leave until he has stoned the jamras on the followingday."
USC-MSA web (English) reference: Book 20, Hadith 223
Arabic reference: Book 20, Hadith 920