It is narrated from Sayyiduna Sa'd bin Malik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Soon there will be a tribulation in which the one sitting will be better than the one standing, the one standing will be better than the one walking, the one walking will be better than the one running, the one running will be better than the one riding, and the one riding will be better than the one who spurs his mount on." This hadith is sahih (authentic) on the condition of Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it. This has become a large chapter which the two Shaykhs did not record, whereas Imam Abu Dawud al-Sijistani (may Allah have mercy on him) recorded it in his "Sunan", which is sahih according to his condition, and Abu Dawud is one of the imams of this science.