Is it established that the Prophet (peace be upon him) saw his Lord in a dream in the form of a man? What is the explanation of this hadith, and is it authentic?

What is authenticated is that the Prophet, peace and blessings be upon him, saw his Lord in a dream in the best of forms. As for what has been narrated with the addition: "in the form of a young man," it is a rejected narration (munkar) and not authentic. Imam Ahmad and a group of scholars, such as Ibn Hibban, Al-Dhahabi, and Ibn Hajar, have denounced it due to the weakness of its chain of transmission.