Tafsir of Al-Hashr 59:3

(And had Allah not decreed for them exile) meaning, the forced departure or the exiting from their homelands in that horrendous manner, (He would have punished them in this world) by killing, just as He did with the people of Badr and others, or just as He, Glory be to Him, did with the Banu Qurayza in the fifth year, since wisdom would necessitate it had He not decreed exile for them. It is said: "I exiled the people from their homes," meaning I forced them out of them and made them leave. And "they exiled from it" means they left and departed. It is also said: "He exiled them" (jalāhum). Some differentiate between jalā’ (exile) and ikhrāj (eviction) by stating that jalā’ occurs with one’s family and children, whereas ikhrāj may occur while the family and children remain. Al-Mawardi said: Jalā’ can only refer to a group, while ikhrāj can refer to an individual or a group. It is also pronounced jalā’ with a hamza (glottal stop) and without an alif, like naba’ (news); this is how Al-Hasan ibn Salih, his brother Ali ibn Salih, and Talha recited it. The an is a source particle (masdariyyah), not a lightened particle, and its subject is the pronoun of state (dhamir al-sha’n), contrary to what the phrasing of Al-Kashshaf implies, as Al-Radi has explicitly stated.

(And for them in the Hereafter is the punishment of the Fire) This is a new commencement, not dependent upon the response to "had not" (lawlā). Meaning: If they escaped the punishment of this world—which is killing—by something more difficult for them, which is exile, they have not escaped the punishment of the Hereafter. Thus, their brief enjoyment of life and their making light of the matter of exile for themselves is of no benefit. There is an indication in this that killing is more severe than exile, not because of its essence, but because they reach the punishment of the Fire through it. Exile was preferred only because they perceived it as more difficult, and because they do not believe in the punishment of the Fire that lies before them, or they do believe in it but do not care for it at all. It is not considered a circumstantial clause (haliyyah) because it would require interpretation due to the lack of simultaneity.