Abu Said relates that the Prophet (saas) said: ...And Allah will later send one from my Ahl al-Bayt to fill a world that is filled with oppression with justice instead. The dwellers in the Earth and the heavens will be pleased with him [the Mahdi (as)]. The Earth will cause all its plants to flourish for them and the sky will constantly cause rain to fall down on them... BECAUSE OF ALL THE BOUNTY THAT ALMIGHTY ALLAH SENDS DOWN TO THE EARTH, THE DEAD WILL WISH TO LIVE AGAIN.
(Al-Bayan, p. 72, Al-Sawaiq Al-Muhariqa, p. 161, Yanabi Al-Mawadda, Vol. 2, p. 177)