841 – Abū Saʿīd al-Khudrī reported that he heard the Prophet ﷺ say: “When any of you sees a dream that pleases him, it is from Allah; let him praise Allah for it and relate it.” In one version he added, “Let him relate it only to someone he loves.” “And if he sees anything else that he dislikes, it is from Satan; let him seek refuge from its evil and tell it to no one, for it will not harm him.” Agreed upon.

Explanation
Imām al-Nawawī, in his “Chapter on Dreams and What Relates to Them,” writes: The term rūʾyā means a dream seen while asleep. When a person sleeps, Allah takes his soul—a minor form of death, as Allah the Exalted says: “He is the One who takes you by night and knows what you have done by day; then He sends you back so that an appointed term may be completed” (6:60). He also says: “Allah takes souls at the time of their death and those that have not died during their sleep” (39:42).

In this minor death the soul goes wherever Allah wills. Hence one of the supplications prescribed for sleep is to say: “O Allah, by Your name I lay down my side, and by Your name I raise it; so if You take my soul, forgive it and have mercy upon it, and if You send it back …”