Abu Hurairah (RA) reported: I heard Allah's Messenger (ﷺ) as saying: He who saw me in a dream would soon see me in the state of wakefulness, or as if he saw me in a state of wakefulness, for the satan does not appear in my form.
Narrated Abu Huraira: I heard the Prophet saying, "Whoever sees me in a dream will see me in his wakefulness, and Satan cannot imitate me in shape." Abu `Abdullah said, "Ibn Seereen said, 'Only if he sees the Prophet in his (real) shape.'"
Maulana Dawood Raz
Hadith Commentary: So it will be the Messenger of Allah (sallallahu alayhi wa sallam) himself.
Source: Sahih Bukhari: Commentary by Maulana Dawood Raz, Page: 6993
Abu Hurairah said: I heard the Messenger of Allah ﷺ say: He who sees me in a dream will see me when awake or as if he will see me when awake, for the devil does not take my likeness.
Shaykh Umar Farooq Saeedi
Benefits and Issues: This is a unique characteristic of the Prophet (sallallahu alayhi wa sallam): That Satan cannot assume your form. However, it is possible that he may appear in another form and create the illusion that this is the Messenger of Allah (sallallahu alayhi wa sallam). Therefore, it is necessary that a person compares the form he saw with those characteristics which are mentioned in the books of hadith. Or he should seek confirmation from a person of knowledge. The late father, Sheikh Abdul Aziz Saeedi rahimahullah, was once told by an innovator, with great enthusiasm and passion, that he had seen the Noble Prophet (sallallahu alayhi wa sallam) in a dream. When my father asked for details, he replied that he had seen a luminous personality with a white, radiant beard. My father immediately recited "La hawla wa la quwwata illa billah" and clarified that you have seen a devil. In short, the one who sees the Noble Prophet (sallallahu alayhi wa sallam) in a dream will see him while awake on the Day of Resurrection and will attain a special closeness. Otherwise, other believers will also see you (sallallahu alayhi wa sallam).
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 5023