﴿ وَلَا يَسْتَطِيعُونَ لَهُمْ نَصْرًۭا وَلَآ أَنفُسَهُمْ يَنصُرُونَ ﴾

“and neither are able to give them succour nor can succour themselves,”

and who are not able to give them that is those who worship them any help nor can they help themselves? by defending themselves against someone intending to damage them by breaking them or otherwise the interrogative is meant as a rebuke.