Hadeeth of 'Abdullah bin Ja'far bin Abi Talib

It was narrated from "Abdullah bin Ja"far that the Messenger of Allah (ﷺ) said:

"Whoever is not sure about his prayer, let him prostrate twice after he says the salam."

It was narrated from "Abdullah bin Ja"far that he gave his daughter in marriage to al Hajjaj bin Yoosuf and said to her:

When he enters upon you, say: There is no god but Allah, the Forbearing, the Most Kind; glory be to Allah, the Lord of the mighty Throne; praise be to Allah, the Lord of the worlds. And he said that when the Messenger of Allah (ﷺ) was worried about something, he would say these words. Hammad said: I think he said: And he could not touch her.