Prophet Muhammad was a brutal dictator who murdered all opponents. He had followers who missed prayer burnt alive in their homes. A woman who had committed adultery was stoned to death in front of her new born baby. At massacre of Banu Qurayza, Muhammad ordered 600/900 Jews behead. Young Jewish boys pants were pulled down and those with the slightest trace of pubes were taken away and beheaded. (Abu Dawud 4390). He was a monster with no human face.
Muhammad, a monster with no human face said it would be permissible to kill a child who has no prospect of accepting Islam.