"And those who disbelieved will be driven to Hell in groups," meaning: group after group, up to His saying:
﴿وَسِيقَ الَّذِينَ كَفَرُوا إِلَى جَهَنَّمَ زُمَرًا﴾ أَي: فوجًا فوجًا , إِلَى قَوْله:
