كَلَّا لَئِن لَّمْ يَنتَهِ لَنَسْفَعًۢا بِٱلنَّاصِيَةِ
Kalla la illam yantahi la nasfa'am bin nasiyah
No! If he does not stop, We shall drag him by his forehead––
No indeed! If he does not stop, we will seize him by the forelock—
The questions that run from verse nine stop at this one. Safaʿa is to seize and drag, and the nāṣiya is the front hair, where you take hold of a horse to lead it or a captive to make him walk. A man who stood over someone at prayer is answered with the grip used on an animal being led away.