Tafsir of Al-Isra 17:83-84

{And when We bestow favor upon man} with health and abundance, {he turns away} from the remembrance of Allah, as if he is independent of Him and self-sufficient.

{And he distances his side}—this is an emphasis on his turning away. For "turning away" from a thing means to turn one’s face from it, while "distancing the side" means to turn one’s flank away and present one’s back. He intended arrogance, for that is the habit of the arrogant.

{And when evil touches him}—such as poverty, illness, or any calamity—{he becomes} intensely despairing of the mercy of Allah. (Note: Do not despair of the mercy of Allah). It is also recited as wa-nā’a bi-jānibihi (with the lam preceding the ayn), similar to the recitation of rā’a for ra’ā. It is also possible that it is derived from nā’a, meaning "to rise up."

{Say, "Each works according to his manner"}—that is, according to his doctrine and the path that corresponds to his state in guidance or misguidance. This is derived from the saying, "a road with shawākil (branches)," which are the paths that diverge from it. The proof for this is His saying: {For your Lord is most knowing of who is best guided in way}—that is, most upright in doctrine and path.

{And they ask you, [O Muhammad], about the soul. Say, "The soul is of the affair of my Lord. And you have not been given of knowledge except a little."}