Hazrat Amr bin Shu'aib narrates from his father and grandfather, who say that the Messenger of Allah, peace and blessings be upon him, said: "When any one of you is frightened in his sleep, he should say::: I seek refuge in the perfect words of Allah from the anger of Allah and His evil punishment, and from the evil of His servants, and from the evil of the devils, and from the evil of those who are present." Thus, Hazrat Abdullah used to teach these words to his intelligent children, and for those children who were not yet understanding, Hazrat Abdullah would write these words and hang them around their necks.