Muhammad b. `Ali Majiluwayh narrated to us from his uncle Muhammad b. Abi’l Qasim from Ahmad b. Abi `Abdillah from his father from `Abdullah b. al-Mughira and Muhammad b. Sinan from Talha b. Zayd from Abi `Abdillah al-Sadiq . He said: My father would say:

There is nothing more corrupting to the heart than sin. Sin settles in the heart and remains there until it overcomes it, turning it upside down.