The one who will revenge for Imam Ḥusayn (pbuh)’s blood, will not exceed the [just] limit in slaying [of the enemies]
… And whoever is slain unjustly, we have indeed given to his heir authority, so let him not exceed the just limits in slaying; surely he is aided. (Holy QurʾÄn, Surah 17, Verse 33)
[In this regard], there is a ḤadÄ«th which reads: The [above] verse is about Imam Ḥusayn (pbuh) and Imam ZamÄn (mgehr); the deceased is Imam Ḥusayn (pbuh) and his avenger is Qa’im [Imam MahdÄ« (mgehr)].