Silsilat al-Ahadith al-Sahihah

Sayyiduna Fadl bin Abbas (may Allah be pleased with them both) narrates that when the people returned on the evening of Arafah and the morning of Muzdalifah, the Messenger of Allah (peace and blessings be upon him) said to them: "Adopt calmness." At that time, he himself was restraining his camel (from moving fast), until he entered Mina and descended in the valley of Muhassir. The Prophet (peace and blessings be upon him) said: "Take care to collect pebbles (the size of chickpeas or beans) with which the Jamrah is to be struck."