Possible meanings are 1) Achish demands that his servants explain why they have brought David to him or 2) Achish is scolding them with a rhetorical question. AT: "You should have known not to bring him to me." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This rhetorical question is a rebuke. AT: "There are enough madmen here who waste my time. You should not have brought this fellow to behave like one in my presence." (See: [[rc://en/ta/man/translate/figs-rquestion]] and [[rc://en/ta/man/translate/figs-explicit]])
This rhetorical question can be translated as a statement. AT: "Do not allow this fellow to enter my house." (See: [[rc://en/ta/man/translate/figs-rquestion]])