What is the explanation of the hadith: "The hope of my Ummah is one hundred years," and what are the indications and signs of Qadhf (being pelted/accused), Khasf (sinking into the earth), Rajf (shaking/trembling), and the sending of the muzzled devils mentioned in the hadith, and when do these matters occur?

The aforementioned hadith is not authentically attributed to the Prophet, peace and blessings be upon him. Al-Hakim narrated it with the wording mentioned by the questioner, and Imam Ahmad narrated it with different wording. Both narrations have weak chains of transmission.

Al-Dhahabi said about Al-Hakim's chain of transmission: "Its chain is obscure (muthlim)." The verifiers of Al-Musnad said about Ahmad's chain of transmission: "Its chain is weak." Ibn al-Jawzi said: "This hadith is not authentic."

Therefore, there is no need to search for its explanation or the timing of the events mentioned within it.