Quran 69:32 from Surah Al-Haaqqa on Divine Marvels.
ثُمَّ فِي سِلۡسِلَةٖ ذَرۡعُهَا سَبۡعُونَ ذِرَاعٗا فَٱسۡلُكُوهُ
English translation: Then into a chain its length (is) seventy cubits insert him
Transliteration: thumma fi sil'silatin dhar'uha sab'una dhira'an fa-us'lukuhu