2 Samuel 17:15-17

Then Hushai said to Zadok and Abiathar the priests, “Thus and so did Ahithophel counsel Absalom and the elders of Israel, and thus and so have I counseled. Now therefore send quickly and tell David, ‘Do not stay tonight at the fords of the wilderness, but by all means pass over, lest the king and all the people who are with him be swallowed up.’” Now Jonathan and Ahimaaz were waiting at En-rogel. A female servant was to go and tell them, and they were to go and tell King David, for they were not to be seen entering the city.