Tafsir of Sad 38:47

"And indeed, they are, to Us, among the chosen," meaning the selected ones from among their fellow kind. Regarding this, there is a well-known morphological adjustment (i'lal). As for "to Us" ('indana), it is permissible for it to be connected to the predicate, or for it to be connected to an omitted element indicated by "among the chosen," meaning: and indeed, they are chosen to Us. It is not permissible for it to be connected to the aforementioned "the chosen" (al-Mustafayn), because the al in it is relative (mawsulah), and mustafayn is the predicate of the relative clause (silah). The complement (ma'mul) of a relative clause may not precede the relative noun, lest it necessitate the precedence of the clause over the relative noun. This has been objected to by stating that we do not concede that the al is relative, as it does not denote an occurrence. Even if it were conceded, the preceding element is an adverbial phrase (zarf), and regarding such, there is a latitude that does not exist for others.

The most apparent interpretation is that the sentence is a conjunction to what precedes it, and it is emphasized for the sake of greater concern regarding their status before Allah, the Exalted, as being among the chosen of the people—the virtuous (al-akhyar).

"The virtuous" (al-akhyar): Those who are superior in goodness. It is the plural of khayyir—which is the opposite of sharr—and is originally an elative form (af'al al-tafdil). It is the standard rule for an elative form not to be pluralized as af'al; however, because of the necessity of lightening it—to the extent that akhyar is not said except as an anomaly or out of necessity—it was treated as if it possessed an original structure. It is also said that it is the plural of khayyir (with the ya doubled) or khayir (with the ya lightened), like amwat (dead) as the plural of mayyit (with the ya doubled) or mayit (with the ya lightened).