It is narrated from Mujahid, he says: Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) asked me: Do you know how vast Hell is? I said: No, I do not. He said: Indeed, we do not know, but (it is certainly so vast that) the distance between the earlobe and the shoulder of one inhabitant of Hell will be seventy years, and in it will flow valleys of pus and blood. I said: Rivers of pus and blood? He said: Not rivers, valleys, valleys. Then he said: Do you know how spacious Hell is? I said: No, I do not. He said: Indeed, we do not know how spacious it is. However, Sayyida Aisha Siddiqa (may Allah be pleased with her) narrated to me that she asked the Messenger of Allah (peace and blessings be upon him) about the statement of Allah, the Exalted: {وَالْاَرْضُ جَمِیْعًا قَبْضَتُہُ یَوْمَ الْقِیَامَۃِ وَالسَّمٰوَاتُ مَطْوِیَّاتٌ بِیَمِیْنِہٖ} (And on the Day of Resurrection the whole earth will be in His grip and the heavens will be rolled up in His right hand) (Surah Az-Zumar: 67). O Messenger of Allah! Where will the people be at the time of this transformation? He (peace and blessings be upon him) said: They will be on the bridge of Sirat over Hell.

It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him), the Messenger of Allah (peace and blessings be upon him) said: The walls surrounding Hell from all four sides are four; the thickness of each wall is equal to the distance of forty years' journey.