Is the prophets' interpretation of visions definitive, certain, and infallible, or is their interpretation speculative and prone to error, as in Joseph's interpretation of the young man's vision?

What the Prophet, peace and blessings be upon him, conveys regarding matters of Sharī‘ah (Islamic law) is revelation from Allah. However, his personal discretionary actions (ijtihādīyah) admit of conjecture (ẓann) rather than certainty (yaqīn), as indicated by his statement: "I am but a human." Scholars have differed on whether the prophets' interpretations of dreams are revelation or a form of ijtihād (discretionary reasoning) and predominant conjecture (ẓann ghālib), due to their differing understandings of Allah's statement concerning Yusuf (Joseph), peace be upon him: "And [Joseph] said to the one whom he knew would be saved out of the two." The majority view "knew" (ẓanna) here as meaning certainty (yaqīn), while others hold that it is conjecture and not certainty, citing the hadith (definition) of Abu Bakr regarding dream interpretation and the Prophet's, peace and blessings be upon him, statement to him: "You were right in some parts and wrong in some parts." They argue that interpreting dreams through conjecture does not diminish their prophethood, for prophets are infallible in conveying the Sharī‘ah, and any error in discretionary matters is not upheld for a prophet. Moreover, the Prophet's, peace and blessings be upon him, conjecture is not like that of other people; rather, it is a predominant conjecture, rarely erring due to his perfect knowledge, fear of Allah, and intellect.