حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ‏:‏ حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، قَالَ‏:‏ حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي إِسْحَاقَ، عَنْ أَبِي الأَحْوَصِ، عَنْ عَبْدِ اللهِ بْنِ مَسْعُودٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم، قَالَ‏:‏ مَنْ رَآنِي فِي الْمَنَامِ فَقَدْ رَآنِي فَإِنَّ الشَّيْطَانَ لا يَتَمَثَّلُ بِي‏.‏

Anas said

"The Prophet said (Allah bless him and give him peace): 'If someone sees me in his sleep, he has indeed seen me, for Satan cannot impersonate me!' He also said: 'The vision of the believer is one of forty-six parts of Prophethood.'"