The source of specific knowledge available to the Prophets, may Allah bestow peace on them, is either revelation from Allah or their own ijtihad. The information that a Prophet, may Allah bestow peace on him, provides based on the revelation is final and blemish-free. On the issues where a Prophet is not provided direct information by Allah, at the time when he has to make a decision, he would either wait for a revelation on the issue or do ijtihad, deducing a ruling on his own. However, his ijtihad cannot be compared with the process the scholars of Islam follow, for whom the principle is that they will get two rewards for a correct decision and one for an incorrect one. There is no question of an incorrect ijtihad by a prophet, as he is in direct contact with Allah, who protects him from taking a wrong position in a matter involving the Shari’ah.
Prophet Muhammad, may Allah grant and bless him peace, described this in a tradition, as reported by Umme Salama, wife of the Prophet, may Allah be pleased with her. The Prophet ﷺ said, “I will decide between you by my own opinion concerning that on which no revelation has been given.”
Allah sent His Prophets with specific purposes that encompassed divine guidance for worshipping Him and to give messages and laws to human beings so that they lead a virtuous life, pleasing Allah, resulting in success in this world and the Hereafter. The Prophets were intended to be the perfect living examples of the faith and practices taught by Allah through them. The related knowledge provided by them was final and flawless. The body of knowledge they were provided comprised the deen/religion of Islam.
However, there are other issues in human life where no specific knowledge or examples from the prophets are required. Men gather that knowledge by their own experience and training without any divine intervention, for which Allah has provided them the required intellectual and other abilities. The Prophets are not required to have perfect and final say in those matters. We may use the term ‘affairs of the world’ for these areas of knowledge. Prophet Muhammad, may Allah grant and bless him peace, described this position succinctly, saying, “I only know what my Lord has taught me.”
Someone may have more knowledge of the ‘affairs of the world’ as compared to the Prophets, like the matters of cultivation or production of goods and services, because the Prophets were not sent to teach these. Allah may provide more knowledge to anybody than that to a Prophet, as we find in the case of a person to whom Prophet Musa, may Allah bestow peace on him, was sent by Allah to be taught some of divine affairs. Musa, may Allah bestow peace on him, said to him, “May I follow you on [the condition] that you teach me from what you have been taught of sound judgment?” (The Qur’an 18:66)
Allah is All-Knowing, and He distributes the knowledge as He wills. One of the principles of knowledge-sharing by Allah is to set its different levels for different persons. He elaborates this in the Qur’an: “We raise the status of whom We please. Over every man of knowledge, there is one more knowing.” (The Qur’an 12:76)