Is the Hadith reported from the Messenger of Allah, peace and blessings be upon him: "Whoever drinks harmal for forty mornings, one mithqal each day, wisdom will illuminate his inner self, and he will be cured of seventy-two afflictions, the least of which is leprosy" authentic or weak, and is it permissible to drink harmal?

The hadith was not found after searching for it in the well-known hadith books. A similar hadith was mentioned in Ibn al-Jawzi's book "Al-Mawdu'at" (Fabricated Hadith), stating that a prophet complained to Allah about the cowardice of his people, whereupon Allah revealed to him to command them to drink harmal (Peganum harmala) because it removes cowardice and increases horsemanship. He described it as a fabricated hadith, and it appears that the hadith in question is also fabricated.