In which Surah are "Ulul Nuha" mentioned, and who are "Ulul Nuha"?

"Uli al-nuha" (those of understanding) is mentioned in Surah Taha in the verse: "Indeed in that are signs for those of understanding" [Taha:54]. Al-nuha means intellects or minds, as Ibn Kathir stated that it refers to those with sound and upright intellects. In Lisan al-Arab, "al-nuha" is the intellect and can be both singular and plural.