Where does 馬上 originate from?
According to "互动百科", it's said that during China's ancient times, a general on horseback was on its way to perform an important task, but he was interrupted midtrip when a messenger caught up to him bringing him a message, which stated that the emperor was deathly ill. He immediately turned around and rode back to see the emperor without alighting from his horse (note: riding in the Forbidden City was strictly forbidden), hence the word "马上" to mean "immediately".