﴿ مُهْطِعِينَ مُقْنِعِى رُءُوسِهِمْ لَا يَرْتَدُّ إِلَيْهِمْ طَرْفُهُمْ ۖ وَأَفْـِٔدَتُهُمْ هَوَآءٌۭ ﴾

“the while they will be running confusedly to and fro, with their heads upraised [in supplication], unable to look away from what they shall behold, and their hearts an abysmal void.”

as they come hastening muhti‘īna is a circumstantial qualifier with their heads turned upwards to the heaven their gaze their sight returning not to them and their hearts as air devoid of any sense because of their being terror-stricken.