'Runners' in the Bible

Then Adonijah, the son of Haggith, lifting himself up in pride, said, I will become king; and he made ready his carriages of war and his horsemen, with fifty runners to go before him.

And king Rehoboam maketh in their stead shields of brass, and hath made them a charge on the hand of the heads of the runners, those keeping the opening of the house of the king,

and it cometh to pass, from the going in of the king to the house of Jehovah, the runners bear them, and have brought them back unto the chamber of the runners.