Oppression (in Arabic) comes from the word (ظلم). Dhulm means to put something where it does not belong. So, sin (because it places a person’s nature where it should not be, sinful) is a form of oppression; as is associating partners with God (since the norm is to worship God alone).

رَبَّنَا أَخْرِجْنَا مِنْ هَذِهِ الْقَرْيَةِ الظَّالِمِ أَهْلُهَا وَاجْعَل لَنَا مِنْ لَدُنْكَ وَلِيًّا وَاجْعَل لَنَا مِنْ لَدُنْكَ نَصِيرًا (75) }

وَاجِبٌ عَلَى النَّاسِ أَنْ يَفْدُوا الْأُسَارَى بِجَمِيعِ أَمْوَالِهِمْ

While the harm injustice and oppression cause is apparent to most people, where they differ is the degree win which they oppose it. Consider the pagan Qur’eish: consistently rocked by large numbers of claimants to power, and those claimants continued jockeying for authority, they were left with no central authority to settle their disputes. As a response, they allied (حلف الفضول) in the home of ‘Abdullah bin Jad’an to collectively repel injustice and intervene to protect the oppressed. The Prophet (sa) witnessed that alliance as a young man. After he became a prophet and settled in Medina, he said,

The early Caliphs of Islam would confront oppression and injustice head-on. However, during the reign of the first four Caliphs injustice was handled largely by reminding people of their responsibility to God. But, as the Muslim empire grew, the number of Muslims swelled, and life became more complicated. Thus, during the reign of Abd al-Malik bin Marwan, he chose a day to listen to the concerns of the oppressed. If their concerns were problematic or required a judgment, he sent them to al-Qadi Abu Idris al-Awaydai.

During the reign of ‘Umar bin ‘Abd al-Aziz after Sulayman bin ‘Abd al-Malik was buried, Caliph ‘Umar sat and had a caller inform the people that anyone mistreated by Sulayman should make their claim. By the time he was done, everything acquired by Sulayman and his family (The Umayyads) unjustly was returned. Such that a friend said to ‘Umar bin ‘Abd al-Aziz, “Do you not fear the wrath of those you’ve punished?” He responded, “Each day that I fear their wrath instead of the wrath of the Hereafter,

Then the Abbasi Caliph came to power, and it continued that tradition with al-Mahdi, then al-Hadi, then Rashid, the al-Mamun until the reign of al-Muhtadi in the year two hundred and fifty-five after the Migration of the Prophet (sa). It did not stop them, but because of volume, the state delegated the responsibility to judges who appointed case workers who could look into the claims each day. Eventually, these cases were taken to the high court where they were settled.

There are numerous examples of leaders who opposed injustice in Islamic history. I would like to mention one noteworthy example here. Once a man came to the court of al-Mansur ibn abi ‘Amir, claiming that one of al-Mansur’s servants had wronged him. He expressed that he had the man subpoenaed by the court, but he refused to come. Al-Mansur turned to his servant, ordering him to go and stand with the man making the claims. There, in front of al-Mansur, the case was heard. After it was over, the Caliph ordered the servant taken away to “The person in charged of the oppressed,” sentenced and removed from his post. That was in Spain, al-Andalus. What is remarkable is that there was a person, “In charge of the affairs of the oppressed.”