What is the ruling on the recurrence of intentional murder after the guardians of the victim have waived their right and accepted blood money in the first crime: Does the right to retribution in the second crime fall with a waiver, or is it retribution without a waiver or blood money?

If a person intentionally kills a believer, the guardian of the slain has the choice between retribution (qisas), or pardoning freely, or for a bloodwit (diyah). If the killer returns to the crime, the majority of scholars believe that his punishment is in the hereafter, and that the blood guardian has the choice between retribution, or pardoning, or bloodwit. While others, such as Qatadah, Ikrimah, and Al-Suddi, believe that he must be killed definitively, Umar ibn Abd al-Aziz believes that the matter rests with the Imam to decide what he deems appropriate.