It is narrated from Sayyiduna Abdullah bin Ja'far (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "If a person has doubt in his prayer, he should perform two prostrations of forgetfulness while sitting."

It is narrated from Sayyiduna Abdullah bin Ja'far (may Allah be pleased with him) that he married his daughter to Hajjaj bin Yusuf and said to her: When he comes to you, say this: «لَا إِلٰهَ إِلَّا اللّٰهُ الْحَلِيمُ الْكَرِيمُ سُبْحَانَ اللّٰهِ رَبِّ الْعَرْشِ الْعَظِيمِ الْحَمْدُ لِلّٰهِ رَبِّ الْعَالَمِينَ» "There is no deity except Allah, He is Forbearing and Generous, Allah, the Lord of the Great Throne, is free from all defects, all praise is for Allah, the Lord of all the worlds." And he said that when any distress befell the Prophet (peace and blessings of Allah be upon him), he would also say these words. Hammad says: I think the narrator also said that Hajjaj could not reach her.