Muslims are people who follow a religion called Islam, and they believe in certain rules and teachings that help them lead a good and peaceful life. Sometimes, when a Muslim sees someone doing something that goes against these rules and teachings, they might say that they "condemn" it.
When a Muslim condemns something, it means they strongly disagree with it and think it's wrong or bad. It's sort of like saying "I don't like that" or "That's not okay."
For example, if a Muslim sees someone hurting others or being mean to them for no reason, they might condemn that behavior because it goes against the teachings of Islam, which emphasize kindness and treating others with respect.
Overall, when a Muslim condemns something, it means they are speaking out against it and saying that it's not in line with the beliefs and values of their religion.