demanding miracles

أَوْ تُسْقِطَ ٱلسَّمَآءَ كَمَا زَعَمْتَ عَلَيْنَا كِسَفًا أَوْ تَأْتِىَ بِٱللَّهِ وَٱلْمَلَـٰٓئِكَةِ قَبِيلًا

Or you make the heaven fall upon us in fragments as you have claimed or you bring Allāh and the angels before [us]