Tafsir of Al-Mumtahanah 60:3

"Neither your relatives... will benefit you" — This is a rebuttal to what they might imagine to be a valid excuse for adopting [the disbelievers as allies] and showing them affection, namely the protection of relatives and children from the harm of those [disbelievers]. The word rahm (womb/kin) originally refers to a woman's womb, but became widely used for kinship until it became like the literal meaning thereof. Either this is what is intended, or it is used metaphorically for the relative, or an implied possessor is considered with it (i.e., "those of your relatives"). The conjunctive phrase in His saying, "nor your children," supports this interpretation; meaning: neither your kin nor your relatives, nor your children—for whom you ally yourselves with the polytheists and draw near to them in order to defend them—will benefit you.

"On the Day of Resurrection" — by repelling harm or bringing benefit.

"He will judge between you" — This is an initiation [of a new sentence] to clarify the lack of benefit from relatives and children on that Day. That is, Allah the Exalted will separate you because of the terror that necessitates that each of you flees from the other, as expressed by His saying: "On the Day a man will flee from his brother" (80:34). Therefore, it is not appropriate to abandon the right of Allah the Exalted and show allegiance to His enemies for the sake of one whose status is such. The connection—which we indicated—of "On the Day of Resurrection" to the verb preceding it (i.e., lan yanfa‘akum) is the most apparent, though it is permissible for it to be connected to "He will judge" which follows it.

Hamza, al-Kisa’i, and Ibn Waththab read yufassilu with a damma on the ya and a shadda on the sad, in the active voice. Abu Haywah and Ibn Abi ‘Ablah read it likewise, but with a light sad. Talha and an-Nakha‘i read nufassilu with a nun carrying a damma and a shadda, in the active voice. Both of them, along with Zayd ibn ‘Ali, read it with a nun carrying a fatha and a light sad, in the active voice. Abu Haywah also read it with a nun carrying a damma.

Al-A‘raj, ‘Isa, and Ibn ‘Amir read yufsalu with a ya, a shadda on the sad, in the passive voice. The majority of the reciters read it similarly, but with a light sad. The deputy of the verb (the subject of the passive) is either "between you" (baynakum)—which is indeclinable with a fatha due to its attachment to something deeply rooted in being indeclinable, as has been said—or it is the pronoun of the verbal noun understood from the verb (i.e., the separation will take place).

"And Allah is All-Seeing of what you do" — He will recompense you for it.