It is narrated from Sayyiduna Fadl bin Abbas (may Allah be pleased with them both) that the Noble Prophet (peace and blessings be upon him) said on the evening of Arafah and the morning of Muzdalifah, when people set out for Mina: "Go slowly," and the Prophet (peace and blessings be upon him) himself was restraining his camel (from moving fast), until when he entered the valley of Muhassir, he let the camel move quickly.
Hadith Referenceسنن دارمي / من كتاب المناسك / 1929
Abu al-Zubair also narrated the hadith as before. Imam Darimi, may Allah have mercy on him, said: «ايضاع» refers to the fast running of a camel and «ايجاف» refers to the fast running of a horse.
Hadith Referenceسنن دارمي / من كتاب المناسك / 1930