So ask them whether their creation is difficult or (of those others) whom We created, We certainly created them from sticking clay.
The term ‘Akhliqu’ meaning ‘I make’ is used by Isa (PBH) 3:49. i.e. ‘Khalqa’ can be used for the fabrications or inventions of mankind too. In view of this Allah (SWT) is probably asking man whether his inventions are difficult or that which (i.e. the whole universe) which Allah (SWT) has created which includes the creation of man from clay.