The Horse used for Conveying Posts

Now the watchman standing on the tower in Jezreel saw Jehu’s troops approaching, and he called out, “I see a company of troops!” “Choose a rider,” Joram commanded. “Send him out to meet them and ask, ‘Have you come in peace?’” …

Mordecai wrote in the name of King Xerxes and sealed it with the royal signet ring. He sent the documents by mounted couriers riding on swift horses bred from the royal mares.