Tafsir of Al-Ma'aarij 70:21

"Good": wealth, affluence, or health.

"Manūʿan" (ungrudging/withholding): one who is excessive in withholding and parsimony.

The first "When" (wa-idhā) is an adverbial condition for "impatient" (jazūʿan), and the second is for "withholding" (manūʿan). Both descriptions, according to what some of the eminent scholars have chosen, are explanatory adjectives (ṣifatān kāshifatān) for "impatient" (halūʿan), which functions as a circumstantial state (ḥāl), as is most appropriate regarding what you have heard from Ibn Abbas and others.

Others have said the three descriptions are circumstantial states (aḥwāl). It is said they are prospective (muqaddarah) if one intends the human’s actual possession of these traits; for, at the time of creation, he was not like this, and these traits only manifested after the completion of his intellect and his entry into the realm of religious obligation. The verification of this is that if one intends the human's possession of the origin of these matters—from the manifest affairs and universal dispositions within which these traits are included potentially—then there is no obstacle for the People of Truth (Ahl al-Ḥaqq) in God Almighty creating the human and tempering him upon this.

There is disagreement regarding the removal of these traits. Some say they are removed through discipline and moral training; were it not for this, there would be no benefit in forbidding or prohibiting them, and they are not inherent necessities of the essence (lawāzim al-māhiyyah). Just as God Almighty created them, He can remove them. Others say they do not vanish but are merely concealed, and the person is restrained from their outward manifestations, as it is said: And nature in the human does not change. This disagreement applies to all natural dispositions. Some scholars stated that matters stemming from the core temperament (aṣl al-mizāj) do not change, whereas those stemming from accidental factors may change.

Al-Zamakhshari held that the speech contains a metaphor. He said: The meaning is that impatience and withholding affect the human, and they are so firmly rooted in him that it is as if he were molded and imprinted with them, as if it were an innate and necessary matter beyond his choice. This is like the Almighty’s saying: "Man was created of haste" (Qur'an 21:37), for when he is in the womb or the cradle, he does not possess this impatience (halaʿ), and because this is a censure, and God Almighty does not censure His own actions. The proof for this is the exception of the believers who struggled against their souls and compelled them toward hardships, divorcing them from desires until they were neither impatient nor withholding.

This view was criticized by the argument that, in the cradle, the human is impatient; he rushes toward the breast and desires suckling, and if pain touches him, he is impatient and cries, and if he grasps something and is competed for it, he withholds it with the flailing and crying within his power. As for the womb, his state is unknown. Furthermore, the name "human" applies to him after birth, so what follows birth is what is considered. The censure pertains to the trait as it subsists in the servant, as has been verified in its appropriate place.

The exception is either disjunctive (munqaṭiʿ), for when the Almighty described those who turned away and retreated, explaining it by their impatience and alarm, He said: “But the observers of prayer” (Qur'an 70:22)—standing in opposition to those others who are in gardens. Then He returned to the former and said: "So what is the matter with those who disbelieve?" (Qur'an 70:36), using the fa for specification after generalization, and returning to the beginning, as they are the mockers whose questioning opened the Surah. Or, it is conjunctive (muttaṣil), on the premise that their nature did not persist in impatience; for since the first (the mention of impatience) was an explanation, it implies a nature persistent in impatience and alarm, except for those who pray, for their nature did not persist in that. Thus, the objection is averted that if the impatience present in the cradle were intended, the exception of those who pray would not be valid, because they were like others in their state of childhood.

This exception is what is contained in the Almighty’s saying: [...the exception...]