What is reported from the Prophet (peace be upon him) regarding the appearance of the Awaited Mahdy and the descent of `Isa (Jesus, peace be upon him)?
As for Al-Mahdy, many Hadiths were reported which indicate that he will preside over this Ummah (community). You should refer to the Sunan (Hadith compilations classified by jurisprudential themes) of
Abu Dawud and
Ibn Majah, and other books of Sunnah, as these Hadiths are mentioned there. There is no Sahih (authentic) Hadith specifying what era he will appear in. As for the descent of `Isa (peace be upon him), you should refer to the book entitled Al-Tasrih fi ma Tawatara fi Nuzul Al-Masih and the Tafsir of
Ibn Kathir for (Part No. 3; Page No. 141) Allah's statement,
But Allâh raised him [‘Isâ (Jesus)] up (with his body and soul) unto Himself (and he عليه السلام is in the heavens).
As far as we know, there is no Sahih Hadith which specifies the time of his descent. The only piece of information is that he descends after Al-Masih-ul-Dajjal (the Antichrist).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.