﴿ 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:”

(And then insert him in a chain) insert the chain in his anus and extract it from his mouth, and what remains of it turn it round his neck (whereof the length) and width (is seventy cubits) cubits of the angel; it is also said this means: 70 fathoms.