Imam Sadiq (peace be upon him) said: "who ever offer the following supplications after noon and dawn prayers on Friday and other days will not die until he meet with Imam Al-Mahdi (peace be upon him).
اَللّٰهُمَّ صَلِّ عَلٰى مُحَمَّدٍ وَاٰلِ مُحَمَّدٍ، وَعَجِّلْ فَرَجَهُمْ