Imam Hussain (AS) declared justice as the central element of his uprising. Imam Hussain (AS) asked (people): Don’t you see the oppression, don’t you see there is no justice, don’t you see there is no just deed, and don’t you see the injustice is not avoided? If Imam Hussain (AS) is from the prophet (PBUH), [the Prophet of Islam (PBUH) said [1]: Hussain (AS) is from me and I am from Hussain (AS)], if the Prophet (PBUH) was required (by Allah (SWT) to establish justice, Imam Hussain (AS) is the same. Opposing oppression means opposing injustice, if justice is commanded by Allah (SWT), injustice is prohibited by God [2].
[1] Al Irshad, Vol. 2, page 127.
[2] Parts of the speech by the Grand Ayatollah Javadi Amoli, Amol, (01/03/2005).
source : shafaqna