وَلَمَّا جَآءَ أَمْرُنَا نَجَّيْنَا هُودًا وَٱلَّذِينَ ءَامَنُوا۟ مَعَهُۥ بِرَحْمَةٍ مِّنَّا وَنَجَّيْنَٰهُم مِّنْ عَذَابٍ غَلِيظٍ
7:73.
Important Words:
غلیظ (severe) is derived from غلظ which means, it was or became thick, gross, bulky or coarse. غلیظ means thick, gross, etc. It also means rough or rugged; dense or deep; rough manners or conduct; rude, unkind, hard, or ill-natured; vehement or severe; intensely painful (Lane & Aqrab).
Commentary:
The words, by Our special mercy, point to a law of God that when a general calamity overtakes a country, both good and bad people become involved in it. But, as in the time of a Prophet these calamities visit the earth in order to testify to his truth, God so ordains that believers more or less remain immune from them. This comparative immunity of believers from such visitations is due to the special grace and mercy of God, which become, as it were, particularly excited in the time of a heavenly Messenger.
The words عذاب غلیظ (severe torment) are intended to hint that disbelievers will not get immunity from the calamities notwithstanding their efforts; for, like one who gets stuck in thick and deep mud, they will not be able to extricate themselves from it. See the different meanings of the word غلیظ above.
7:73.