Mahmoud describes his life after prison in comparison to his experience in prison as follows; B. Mahmoud's life after prison exposed him to ongoing forms of punishment which extended the punishment of his experience in prison.
What was the experience?
In the story, "Refugee" by Alan Gratz, Mahmoud is an immigrant who had come from Tehran but was imprisoned in the United States. The sudden nature of his arrest and eventual imprisonment made him believe that the sentence given to him was unfair.
Life in prison according to him did not afford people the chance to change positively. So, even after he was released from prison, Mahmoud still could not do much with his life and so he believed that life after prison exposed him to ongoing forms of punishment.
Source: Refugee by Alan Gratz