It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: The truest dreams are those that are seen at the time of Sahar (pre-dawn).
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11650
Hadith Gradingحکم دارالسلام:إسناده ضعيف لضعف دراج فى روايته عن أبى الهيثم