Here’s that portion of the Parade Magazine article from 1997:
A young actor recreated the moment when, at 14, Ben Carson pulled a knife on a classmate and tried to stab him in the abdomen. Only the other boy’s metal belt buckle kept Ben from cutting him and going to prison instead of to Yale. “Oh, that really happened,” Sonya told me. “I sat him down and told him that you don’t accomplish much by being a bully. You accomplish more with kindness than you ever do by being harsh.” Sonya realized that the violence of the streets could easily ensnare her sons, and she made it her job to ensure that that would not happen.