question #1 Sahih Muslim Introduction 79, Introduction, Narration 78 : What is the significance of verifying the authenticity of hadiths through dreams or visions?

‘Hamzah az-Zayyāt and I heard from Abān bin Abī Ayyāsh something like one thousand Ḥadīth’. Alī said: ‘So I met Hamzah then he informed me that he saw the Prophet, peace and blessings of Allah upon him, [in a dream], and he produced for him what he heard from Abān. However he [the Prophet] didn’t recognize any except a small amount [like] five or six [Ḥadīth]’.