قَالَ رَسُولُ اللٌّهِ : لاَ تَقُومُ السَّاعَةُ حَتَّى يَقُومَ قَائِمُ الْحَقِّ مِنَّا وَ ذٌلِكَ حِينَ يَأْذَنُ اللٌّهُ عَزَّ وَ جَلَّ. فَمَنْ تَبِعَهُ نَجَا وَ مَنْ تَخَلَّفَ عَنْهُ هَلَكَ...
The Messenger of Allah (peace be upon him and his family) has said: “The appointed time (of the Day of Resurrection) will not come until the one from among us (the Ahlul Bayt) will rise with the truth and make his advent [Imam al-Mahdi], and this will take place when Allah, the Noble and Grand permits. So whoever obeys him shall be saved, and whoever goes against him will be destroyed…”
Wasa’il ash-Shi’a, Volume 7, Page 325, hadith 6