Hadith 31-294

وَبِإِسْنادِهِ عَنْ عَلِيِ‏ عَلَيْهِ السَّلامُ قالَ: قالَ النَّبِيُ‏ صَلَّى اللهُ عَلَيْهِ وَآلِهِ: لا تَذْهَبُ الدُّنْيا حَتّى‏ يَقُومَ رَجُلٌ مِن وُلْدِ الحُسَيْنِ يَملَؤُها عَدْلاً كَما مُلِئَتْ ظُلْماً وَجَوراً.

According to the same documentation on the authority of Ali (a.s.), the Prophet (S) said, “The world will not end until one from the progeny of Al-Husayn (a.s.) rises and spreads justice all over the world which oppression and force have covered up with darkness.”