How do we respond to someone who weakens the Hadith, "Go with these two sandals of mine, and whoever you meet behind this wall testifying that there is no god but Allah, believing it with certainty in his heart, then give him the good tidings of Paradise," on the grounds that it raises the status of Omar above that of the Prophet, peace be upon him, and who questions the reason for the Prophet's agreement with Omar not to publicize this Hadith, given that it is a divine revelation?

It is not permissible to weaken a Hadith because it poses difficulty for some understandings. It is permissible to prohibit something that is otherwise permissible for fear of mischiefs. Umar ibn al-Khattab, may Allah be pleased with him, prohibited three divorces pronounced in a single sitting from being subject to review. The Prophet, peace and blessings be upon him, prohibited Mu'adh from conveying good tidings to the people lest they become complacent, so the prohibition was for the sake of benefit. Scholars have agreed that the Prophet, peace and blessings be upon him, had the right to exercise ijtihad in worldly matters and to refer to the opinion of others for the sake of benefit. An example of this is what he did when he sent Abu Hurairah to convey the good tidings of Paradise, but Umar, may Allah be pleased with him, stopped him for fear of people becoming complacent.