ʿAmr b. Shuʿayb narrated from his father, who narrated from his grandfather, that the Messenger of Allah ﷺ said: “When one of you becomes frightened during sleep, then let him say: [the above]. For verily, they shall not harm him.” He said: “So ʿAbdullah b. ʿAmr (raḍiy Allāhu ‘anhu) used to teach it to those of his children who attained maturity, and those of them who did not, he would write it on a sheet and then hang it around their neck.” (Tirmidhī 3528) The Messenger of Allah ﷺ said: “A good dream is from Allah, so if anyone of you sees a dream which pleases him, he should not tell anybody about it except to the one whom he loves. And if he sees a dream which he dislikes, then he should seek Allah’s protection from its evil and from the evil of Shaytān. He should spit three times on his left and should not tell anybody about it, lest it might harm him.” (Bukhārī 6986)