What cruel act does Amir and Farid witness while they are at Ghazi Stadium?

The next day, the men attended a soccer match at Ghazi Stadium. It was nothing like Amir remembered, the lush green playing field now turned to dry dirt with two deep holes behind the goalpost. Talibs walked up and down the aisles, whipping anyone who made too much noise. During halftime, Amir discovered the horrifying reason for the two deep holes in the ground; they were to be the graves of two accused adulterers, who would be stoned in front of the thousands of attendees. A cleric announced to the crowd that the "will of Allah and the word of the Prophet Muhammad" said death by stoning was a just punishment for adulterers. As he listened to this distortion of Islam, Amir e what Baba had said years before: "God help us all if Afghanistan ever falls into their hands."