Shmuel Bais 20:22

Then the isha went unto kol haAm in her chochmah. And they cut off the rosh of Sheva Ben Bikhri, and threw it out to Yoav. And he blew a shofar, and they retired from the city, every ish to his ohel. And Yoav returned to Yerushalayim unto HaMelech.