https://www.btstories.com/running-to-the-king/

At first, Hushai didn’t know if Absalom would follow his advice or Ahithophel’s. So he decided to prepare David for the worse outcome. It was prearranged that two runners would deliver to David any communication from Hushai. So he sent them a message delivered by a servant girl saying, “Run to the king and tell him, ‘Don’t spend the night on this side of the Jordan River. Instead, cross over to the other side. If you don’t, you and all the people with you will be destroyed.’” So the men started running toward David.