And they say, 'the Fire shall not touch us, to the end [of the verse: save a number of days'. Say: 'Have you taken with God a covenant? God will not fail in His covenant, or say you against God what you do not know?] They believed that the duration of punishment was commensurate with the duration in which the sin was being committed, not knowing that if the sin constituted a corrupt belief fixed within the soul and a condition deeply-rooted in it so that it becomes a natural disposition, a form of its essence, then it [the sin] becomes a cause for eternal punishment, which is the very meaning of His statement: