They said three things
The green light is flashing. It is our signal to begin. Go ahead. Learn The Chapters of the Fathers. Look at these young boys, older boys, men and scholars. All are busy studying its lessons of how good people behave. Each "mishnah" is a lesson taught by a Tanna - a teacher - who learned how to behave from his teacher, back to the greatest of all teachers, Hashem. As we learn, let us try to make these lessons part of our lives.