﴿ وَلَوْلَا كَلِمَةٌۭ سَبَقَتْ مِن رَّبِّكَ لَكَانَ لِزَامًۭا وَأَجَلٌۭ مُّسَمًّۭى ﴾

“Now were it not for a decree that has already gone forth from thy Sustainer, setting a term [for each sinner's repentance], it would inescapably follow [that all who sin must be doomed at once].”

And but for a decree that had already preceded from your Lord that their chastisement be deferred to the Hereafter it destruction would have been an inevitability their destruction would have been necessary in this world and a specified term fixed for them ajalun musamman a supplement to the pronoun concealed in kāna ‘it would have been’ the separation of both subjects by the predicate of both serves as an emphasis.