Ruling on things that were done at the time of the Prophet (peace and blessings of Allaah be upon him) which he did not know about
Question

                What is the ruling on things that were done at the time of the Prophet (peace and blessings of Allaah be upon him) which he did not know about?
Praise be to Allah.Perhaps minor issues which happened but 
          he did not know about them are not included in that. But with regard 
          to things which were widespread and well known, the basic principle 
          is the hadeeth of Jaabir: “We used to practice coitus interruptus (‘azl) 
          at the time when the Qur’aan was being revealed.”