﴿ ثُمَّ فِى سِلْسِلَةٍۢ ذَرْعُهَا سَبْعُونَ ذِرَاعًۭا فَٱسْلُكُوهُ ﴾

“and then thrust him into a chain [of other sinners like him - a chain] the length whereof is seventy cubits:”

then in a chain whose length is seventy cubits — each cubit being that of an angel’s forearm — insert him after admitting him into the Fire the fā’ of fa’slukūhu does not prevent the verb from being semantically connected to the preceding adverbial clause.