The realm of authorities of Islamic ruler in place of blood guardian

Due to necessity of prevention of wasting human blood, God naturally places the Islamic ruler as the guardian of person who has no guardian. But does the ruler have all authorities that the blood guardian has? And can the Islamic ruler also perform all authorities as the blood guardian and can he change the retaliation into the blood – money or not? Regarding this issue, there are two well-known and unknown theories. According to the well-known theory, the Islamic ruler can forgive retaliation instead of taking blood–money, like other blood guardians on the basis of the two traditions of Abi Vallad, but he has no right of gratuitous forgiveness. According to the second theory, the Islamic ruler can forgive the murderer without taking the blood-money. This paper, in addition to expressing the above-mentioned theories, deals with sunni's point of view, that is correspondent to the well-known theory, and legislator view. Then, by contemplation on the well-known theory and on the basis of a tradition that considers Imam as wise and mature person (Aqeleh) who has no inheritor, and also as a result of including traditions that considers the blood-money which has no inheritor as a part of spoil of war (Anfal) on one hand, and views the Anfal as Imam's right on the other; this paper supports and strengthens the unknown theory.