It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that when the Prophet (peace and blessings be upon him) departed from the plain of Arafat, a group of people began to move ahead quickly. The Prophet (peace and blessings be upon him) instructed a person to announce: "O people! Speeding up horses and mounts is not an act of virtue." Ibn Abbas (may Allah be pleased with them both) says that after that, I did not see any mount stretching out its hand (i.e., moving quickly) until we reached Muzdalifah.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 2264
Hadith Gradingحکم دارالسلام:حديث صحيح، المسعودي مختلط، لكن روي عنه هذا الحديث قبل الاختلاط