What is the chain of transmission for the Hadith: "Whoever surrenders himself to Allah for forty days, sources of wisdom will flow from his heart to his tongue," narrated by Abu Dawud and Abu Nu'man in "Al-Hilyah"?

The narration: "Whoever surrenders himself to Allah for forty days," with this exact wording, has not been found. However, what is well-known is with the wording: "Whoever dedicates himself sincerely to Allah the Almighty for forty days." This narration has been reported through several chains:

Hadith of Abu Ayyub (may Allah be pleased with him): "Whoever dedicates himself sincerely to Allah the Almighty for forty days, springs of wisdom will appear on his tongue." Its chain of transmission is weak due to the unknown status of Muhammad ibn Ismail, and criticisms regarding Yazid al-Wasiti and al-Hajjaj, and the断 chain of transmission between Mak'hul and Abu Ayyub. Hadith of Abu Musa (may Allah be pleased with him): "Whoever practices asceticism in the world for forty days and sincerely devotes himself to worship therein: Allah the Almighty will bring forth on his tongue springs of wisdom from his heart." Its text is denounced (munkar), and Abd al-Malik ibn Mihran is unknown. Hadith of Ibn Abbas (may Allah be pleased with both of them): "Whoever dedicates himself sincerely to Allah for forty mornings, springs of wisdom will appear from his heart on his tongue." Its chain of transmission is weak; it contains Sawwar ibn Mus'ab, whose narrations are abandoned, and Aamir ibn Sayyar, who is unknown.

Therefore, this hadith is weak and not authentically reported from the Messenger of Allah (peace be upon him). The strongest of its reports is that of Mak'hul, which is mursal (lacks a companion in its chain) and weak.