Tafsir of Al-Insan 76:27-28

{Indeed, these} disbelievers {love the immediate}—they prefer it over the Hereafter, as in His saying: {Nay, you prefer the life of the world} (Al-A‘lā: 16).

{And they leave behind them}—meaning before them or behind their backs, paying it no heed—{a heavy Day}. The term "heavy" is used metaphorically for its intensity and terror, like a heavy object that burdens its bearer. Similar is: {It will be heavy in the heavens and the earth} (Al-A‘rāf: 187).

{We created them and strengthened their forms}: Al-asr (strengthening/binding) means tying and securing. From this comes asara al-rajul (the man was bound) when he is secured with leather straps, which is al-isār (shackling). A horse is ma’sūr al-khalq (firmly built), and a shield is ma’sūr (bound) with sinew. The meaning is: We firmly connected their bones to one another and secured their joints with nerves. Similar to this is the saying: "A girl of firmly-knit and well-woven build."

{And when We will}, We will destroy them and {replace them with others like them} in the strength of their build—meaning the second creation. It is also said: It means We will replace them with others who obey. It is grammatically appropriate for this to be introduced with in (if) rather than idhā (when), as in: {And if you turn away, He will replace you with a people other than you} (Muhammad: 38), and {If He wills, He can do away with you} (An-Nisā’: 133).

{Indeed, this is a reminder, so whoever wills, let him take a path to his Lord. And you do not will except that Allah wills. Indeed, Allah is ever Knowing, Wise. He admits whom He wills into His mercy, but the wrongdoers—He has prepared for them a painful punishment.}