'Horseback' in the Bible

and let the apparel and the horse be delivered to the hand of one of the king's most noble princes, that they may array the man therewith whom the king delighteth to honor, and cause him to ride on horseback through the street of the city, and proclaim before him, Thus shall it be done to the man whom the king delighteth to honor.

And he wrote the name of king Ahasuerus, and sealed it with the king's ring, and sent letters by post on horseback, riding on swift steeds that were used in the king's service, bred of the stud: