I came across to this video.
Imam and people around him are flogging themselves. Why?
What does this mean in Islam? any hadith or Quran to back this up?
PS: I am not being funny or insulting anyone.
This is part of a practice that is done during the month of Muharram called as "matam" or "mourning". It was introduced into Shia Muslims to mourn the matyrdom of Hussain(ra) the grandson of prophet(pbuh) in the battle of Karbala. This practice of self beating to mourn is not accepted by mainstream Islam and many Shia muslims too.
One thing all Muslims agree, that the martyrdom of the grandson of the prophet(pbuh) is a sad event.
This practice of "self beating" was NOT done during the lifetime of the prophet(pbuh) or during lifetime of his grandson Hussain(ra) whose martyrdom is being mourned. Rather it was introduced later.
Initially, it started as only "days of mourning" , where people would refrain from super happy things like marriages etc. BUT as time passed by, practices of self-beating, political processions and rhetoric cursing sessions were introduced from local customs and political situations.
The goal of this mourning is to Remembrance of message of Imam Hussain (a.s.) who wanted to save Islam from being destroyed by Umayyads. he wanted to say to all humans that there are two different Islam.
After Karbala tragedy majority of Iranians converted from Sunni Islam to Shia Islam after thinking and analyzing Battle of Karbala and facts leading it.
However each people do mourn by their local culture and some uneducated people do mourn by harming to their body which is rejected and declared as Haram by Shia scholars and Maraje. But still in few locations some people do mourn with harm. such cases are few but the enemies of Shia Islam for making propaganda spread them in Internet as if it is accepted by shia scholars.
Shia Muslims do mourning for Hussain (a.s.) at Ashura day of each year slightly with no harm and with reciting some poems about happenings in Karbal for slaughtering Imam Hussai as and 72 of his pious companions and his infant baby and taking his family and women as prisoners and taking them to Castle of Yazid at Shaam.
I personally have not seen even one case of slapping head at Ashura. it was for past years and recently it is very rare. but videos are still spreading in Internet by who hate Shia. A typical mourning usually is with poems and hearing to speeches.
This action (slapping head with bleeding) is called Tatbir and here you can find a list f Fatwa of Shia Maraje about it:
This is not an official website of scholars but it is true and fatwa of each scholar can be found in his official website.
Also there are many fake propaganda website against shia claiming Tatbir is accepted by Shia scholars and show fake fatwa of shia scholars to defame shia Islam.
One example of them is http://imamshirazi.com/tatbir%20fatawa.html which is a 100% fake website.
Please take care to believe any shia fatwa only from official website of scholars.
to clear misunderstandings please note according to shia scholars mourning for Hussain a.s and hazrat Abbas including injury and harm to body is Haram. but without injury it is recommended and has very high reward.