What is the wisdom behind concealing the graves of all prophets, except for the grave of the Messenger, may Allah bless him and grant him peace?

There is no explicit text in Islamic law commanding the concealment of prophets' graves. Most prophets' graves have disappeared over time and are no longer known with certainty, except for the grave of the Prophet Muhammad, peace and blessings be upon him, whose location has been transmitted through continuous succession (tawatur), and the grave of Khalil Ibrahim, peace be upon him, whose location the majority agree upon.

There is no legal benefit in knowing the locations of prophets' graves, and their preservation is not considered part of the religion. If it were, Allah would have preserved them. The reason behind asking about their locations is often for the purpose of praying and supplicating at them, which are forbidden innovations.

Umar ibn al-Khattab concealed the grave of Prophet Daniel to prevent people from being tempted by it and to block the means to polytheism. As for the grave of Prophet Muhammad, peace and blessings be upon him, he himself warned against taking it as a place of celebration ('id) or a mosque. He cursed the Jews and Christians for taking the graves of their prophets as mosques, and were it not for that, his grave would have been made prominent.