Tafsir of An-Nisa' 4:52

(Those) who are distant and cast away in misguidance, (whom Allah has cursed,) meaning: He has distanced them from His mercy and expelled them. The demonstrative pronoun is the subject, and the relative pronoun is the predicate; the sentence is an initiation to clarify their state and reveal their ultimate fate.

(And he whom Allah curses,) meaning: whom He distances from His mercy, (you will never find for him a helper,) meaning: a protector who prevents the torment from him, whether in this world or the hereafter, through intercession or otherwise. In this is a clarification of their deprivation from the fruit of their seeking support from the polytheists of Mecca, and an allusion to the promise to the believers that they are the ones who are supported wherever they may be, in contrast to these people, for they are those whom Allah, the Exalted, has brought near; and he whom Allah brings near, you will never find for him one who forsakes him.

In the employment of the word "lan" (never), the addressing of every individual for whom this is applicable, the singularization of "naseer" (helper) as an indefinite noun, and the expression of its non-existence through the negation of finding—which implies a preceding search—attributed to the general addressee, there is a manifestation of their eternal deprivation from attaining what they hoped for entirely that is not hidden. Even if the hyperbole in "naseer" is considered directed toward the negation, as has been said regarding His statement, may He be glorified: "And your Lord is never unjust," the force of this indication is further strengthened.