Jabir reported Messenger of Allah ﷺ as saying: He who saw me in sleep in fact saw me, for it is not possible for the satan to appear in my form;
and he also said: When any one of you sees a hulm he should not inform anyone, for it is a sort of vain sport of devil in the state of sleep.

وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، ح وَحَدَّثَنَا ابْنُ رُمْحٍ، أَخْبَرَنَا اللَّيْثُ، عَنْ أَبِي، الزُّبَيْرِ عَنْ جَابِرٍ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " مَنْ رَآنِي فِي النَّوْمِ فَقَدْ رَآنِي إِنَّهُ لاَ يَنْبَغِي لِلشَّيْطَانِ أَنْ يَتَمَثَّلَ فِي صُورَتِي " . وَقَالَ " إِذَا حَلَمَ أَحَدُكُمْ فَلاَ يُخْبِرْ أَحَدًا بِتَلَعُّبِ الشَّيْطَانِ بِهِ فِي الْمَنَامِ " .