And indeed you knew those amongst you who transgressed in the matter of the Sabbath (i.e. Saturday). We said to them: “Be you monkeys, despised and rejected.”
Meaning:-
Transgressed: to violate a law, command, moral code, etc.; offend; sin.
Sabbath: the seventh day of the week, Saturday, as the day of rest and religious observance among Jews and some Christians or any special day of prayer or rest resembling the Sabbath: Friday is the Muslim Sabbath.
Despised: to regard with contempt, distaste, disgust, or disdain.