أَلسَّلاَمُ عَلَيْكَ يَا ثارَ اللّهِ وَابْنَ ثارِهِ وَالْوِتْرَ الْمَوْتُورَ
“Peace be upon you O’ the one who was killed and whose blood has not yet been avenged – and whose avenging is in the hands of Allah and peace be upon you, the son of one who was killed and whose blood has not yet been avenged (Imam ‘Ali b. Abi Talib) and peace be upon you O’ the one who was alone, an individual (killed).”
In order to better understand this line, it is necessary to offer the following introduction.
The custom of the pre-Islamic Arabs was such that each extended family belonged to a particular clan or tribe. If a person of one tribe, such as Bani Mudhirr was killed by someone from Bani Kinaana, then the entire tribe of Bani Kinaana was held responsible for this crime! A person from Bani Mudhirr was “permitted” to kill anyone from the other tribe as retribution – even if that person was not guilty of the killing! Such a form of ‘collective guilt’ was the way of the backward Arabs and can even be seen today!
Islam came on the scene and said that the one who is guilty of the crime is the one who must do the time and that ‘blind revenge’ is not permissible. It is through this custom that rivalries and wars came to a halt. The only people responsible in ensuring that one who was killed was avenged was his immediate family – mother, father, brother, etc...
With this said, we see in another Ziyarat of Imam Husayn that we pray, “And surely you are the (metaphorical) blood of Allah on the earth and you are the blood which has not be avenged by a single person on the Earth and which can not be avenged except by Allah, the One.”
Therefore, the ‘avenger’ mentioned in this Ziyarat is not the avenger of an act done by one person upon another person since in this case it would have been settled between Imam Zaynul Abideen (peace be upon him) and Shimr, Yazid and the others. This is not a killing which could be avenged in a few hours and with the killing of a few people. Rather, this is a case of avenging the death of a person who was the representative of Allah over all of humanity for all time and is something which can only be carried out by the One who had sent such a representative.
In closing, we recall the words of our 6th Imam in Du’a an-Nudbah where he cries out to the one who shall avenge the blood on behalf of Allah, “Where is the one who shall avenge the blood of the murdered Prophets and the sons of the Prophets who were murdered? Where is he one who shall avenge the blood of those killed in Karbala’?”