2 Samuel 15:30-31

30As David was going up the Mount of Olives, he was weeping as he went; his head was covered and his feet were bare. All the people who were with him also had their heads covered and were weeping as they went up.

31Now David had been told, “Ahithophel has sided with the conspirators who are with Absalom. So David prayed, “Make the advice of Ahithophel foolish, O Lord!”