Our master Sadiq (peace be upon him) in the book "Jamaali Ssaliheen" said: among our rights on the Shi'a is to place their hands on their chin after the obligatory prayers and recites the following (3) three times:
يَا رَبَّ مُحَمَّدٍ عَجِّلْ فَرَجَ اٰلِ مُحَمَّدٍ، يَا رَبَّ مُحَمَّدٍ اِحْفَظْ غَيْبَةَ مُحَمَّدٍ، يَا رَبَّ مُحَمَّدٍ اِنْتَقِمْ لِابْنَةِ مُحَمَّدٍ عَلَيْهِمَا السَّلَامُ۔