The Command to be Patient with the Harms of the Disbelievers and a Discussion of what They will rece
Allah commands His Messenger to be patient with what the foolish who reject him among his people say. Allah also commands him to keep away from them in a nice way. This means in a way that is not blameworthy. Then Allah says to him, as a threat and a warning to his people - and He (Allah) is the Most Great, Whose anger nothing can stand before,
وَذَرْنِى وَالْمُكَذِّبِينَ أُوْلِى النَّعْمَةِ
(And leave Me alone to deal with the deniers, those who are in possession of good things of life.) meaning, `leave Me to deal with the rich rejectors, who own great wealth.' For verily, they are more able to obey than others besides them, and they are requested to give the rights (to people) because they have what others do not have.
اِنَّ لَدَيْنَآ اَنْكَالًا وَّجَحِــيْمًا (Surely with Us are fetters and flaming fire, and food that chokes, and a painful punishment...73:12-13). The terrible punishment of the Hereafter is described in these verses. First, there is the mention of ankal which is the plural of nakal. It denotes 'fetter, chain, shackle'. Then, there is the mention of 'flaming fire'. Then, verse [ 13] describes the 'choking food' the inmates of Hell will be given to eat.
The word ghussah literally denotes 'a thing by which one is choked'. For example, a morsel may block the throat in such a way as it can neither be swallowed nor can it be brought up. The inmates of Hell will be given Bari` and zaqqum (thorny fruits) to eat. These fruits fit the description.
Sayyidna Ibn ` Abbas ؓ said: "In it will be thorns of fire that will
choke." [ God save us!].
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 5–13
Literally ‘weighty words’ refers to that order for giving warning which is mentioned in the next chapter, ‘Arise and give warning’ ( 74:2 ). This means inform people about the hazards of the Hereafter. Undoubtedly this is the most difficult task in the world. For this, the missionary has to stand by the pure and unadulterated Truth, even if he becomes a stranger to all his people. He has to tolerate being tormented by the people, so that the relationship between him and his addressees remains unaffected till the last moment. He has to be unilaterally governed by the principles of patience and avoidance of confrontation, so that his status as da‘i should not be damaged.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.