Excerpts from Books and Wikipedia
"In this way he succeeded in uniting millions of people who were divided among themselves either in the name of God or in the name of caste. He said, 'One does not become a Brahmin by birth, one does not become an outcast by birth. One becomes Brahmin by act, one becomes an outcast by act.' Shortly before His passing away from this earth, Buddha made a great promise to His followers who were afraid that His Cause would gradually die away. He said: 'I am not the first Buddha who came upon earth nor shall I be the last. In due time another Buddha will arise in the world, a holy one, a supremely enlightened one endowed with wisdom in conduct, auspicious, knowing the universe, an incomparable leader of men, a master of angels and mortals.'" [Fathea'zam: The New Garden]