Tafsir of An-Nisa' 4:30

(And whoever does that), meaning the killing of a soul only, or that combined with what preceded it of consuming wealth unjustly, or the totality of the previously mentioned prohibitions starting from His saying, Exalted is He: (O you who have believed, it is not lawful for you to inherit women by compulsion), or from the beginning of the Surah up to this point—these are various opinions. The first of these has been narrated on the authority of ‘Ata’, and perhaps it is the most apparent. The remoteness involved in the latter interpretations serves to signify the hideousness of killing a soul and its extreme degree of corruption. The use of the singular demonstrative pronoun [“that”], while assuming there are multiple matters referred to, is based on interpreting them as a single collective preceding subject.

(In transgression), meaning excessive overstepping of the limit. It has also been recited as ‘idwanan with a kasra under the ‘ayn.

(And injustice), meaning the commission of what one is not entitled to. It is said that they both have the same meaning, so the conjunction is for explanation. It is also said that “transgression” refers to encroaching upon others, while “injustice” refers to wronging one’s own soul by exposing it to punishment. In any case, both are in the accusative case as states of being (hal) or as reasons (‘illiyah). It is said that by these two terms, inadvertence, error, mistake, and matters involving legal reasoning (ijtihad) in judgments are excluded.

(We shall cast him into a fire), meaning We shall cause him to enter it and burn him with it. The sentence is the apodosis of the conditional. It is recited as nussulihi with a shadda, and naslihi with a fatha on the nun, from salah—a dialectical variant—similar to aslah. It is also read as yuslihi with the ya at the beginning, and the pronoun refers to Allah, the Exalted and Majestic, or to the fire itself, with the attribution being figurative, as in the case of attributing an action to its cause.

(And that), meaning his being cast into the fire on the Day of Resurrection, (is easy for Allah); it is effortless. No obstacle can prevent Him from it, no repeller can push it away from Him, and no intercessor can intercede regarding it except by His permission. The manifestation of the Glorious Name [Allah] by way of shifting the address serves to cultivate awe and to emphasize the independent nature of this concluding parenthetical statement.