Tafsir of Al-Balad 90:4

That is to say: in toil and difficulty. For he continues to endure various forms of adversity from the time the soul is breathed into him until the time it is extracted, and in whatever lies beyond that.

It is said: "A man is kabida (suffering from liver pain), such that he is akbad," if his liver aches and swells. The usage then broadened until it was employed for every form of toil and difficulty. From this, al-mukabada (the act of enduring) is derived, meaning to undergo hardships, just as it is said, "He kabahu," meaning he destroyed him, the root of which is "he struck his liver." Labid said, lamenting his brother:

O eye, have you wept for Arbad, when we stood, and the adversaries stood, in hardship?

That is, in the intensity of the matter and the difficulty of the situation.

According to Ibn Umar: "He endures [the duty of] gratitude during times of ease, and he endures [the duty of] patience during times of adversity."

According to Ibn Abbas, Abdullah ibn Shaddad, Abu Salih, al-Dahhak, and Mujahid, they said: "It means We created him with an upright stature, standing, and did not make him crawling upon his face." Ibn Kaysan said: "Meaning, his head is upright in his mother’s womb; then, when he is permitted to emerge, he turns his head toward his mother’s feet."

All of these latter views are weak and cannot be relied upon, unlike the first view, which has been narrated by al-Hakim—who authenticated it—and by a group from the predecessors through Ibn Abbas.

Yes, it is possible that the meaning is: "We have created him in a grievous illness," namely the illness of the heart and the corruption of the inner self. This is based on the third of the four interpretations mentioned previously regarding the verse: "I swear by this city, and you are free in this city."

The intended meaning of "man" in that context refers to those whom God Almighty knew, at the time of their creation, that they would neither believe nor perform righteous deeds. However, the apparent meaning—aside from that—is the human species in its entirety.

Ibn Zayd said: "By 'man' is meant Adam (peace be upon him), and by 'hardship' (kabad) is meant the sky," as it is common to refer to the middle of the sky as al-bayda', al-kabidah, al-kabda', and al-kabad (with a fatha followed by a sukun). But this is of no basis at all.