The Book of the Etiquette of Sleeping, Lying and Sitting etc

The Prophet (ﷺ) said, "A good vision (dream) is from Allah and a bad dream is from the Satan. He who sees something in a dream that he dislikes, should blow thrice on his left, must seek Allah's Refuge from the evil of the Satan (i.e., by saying: A'udhu billahi minash-Shaitanir-Rajim). Then it will not harm him."[Al-Bukhari and Muslim].

Messenger of Allah (ﷺ) said, "When one of you sees a bad dream let him blow three times on his left, seek refuge in Allah from the Satan three times (i.e., by saying: A'udhu billahi minash-Shaitanir-Rajim) and change the side on which he was lying."[Muslim].

Messenger of Allah (ﷺ) said, "Of the worst lies are: to claim a false father, or to pretend to have seen what one has not seen (tell a false dream), or to attribute to the Messenger of Allah (ﷺ) what he has not said."[Al-Bukhari].