There is no doubt that more Muslims are killed at the hands of Muslim extremists than non-Muslims. My question is, have Muslim extremist groups paid their penalties for killing Muslims? The Qur’an commands Muslims to pay kaffarah (expiation) for killing a Muslim by mistake even at times of war. I mean they couldn’t be killing them intentionally right because for that the Qur’an is very clear:

But whoever kills a believer intentionally – his recompense is Hell, wherein he will abide eternally, and Allah has become angry with him and has cursed him and has prepared for him a great punishment. (Qur’an 4:93)

So I’m assuming their killing them by mistake? So what is the penalty for a Muslim for killing a fellow Muslim by mistake? Well, let’s see:

And never is it for a believer to kill a believer except by mistake. And whoever kills a believer by mistake – then the freeing of a believing slave and a compensation payment presented to the deceased’s family [is required] unless they give [up their right as] charity. But if the deceased was from a people at war with you and he was a believer – then [only] the freeing of a believing slave; and if he was from a people with whom you have a treaty – then a compensation payment presented to his family and the freeing of a believing slave. And whoever does not find [one or cannot afford to buy one] – then [instead], a fast for two months consecutively, [seeking] acceptance of repentance from Allah . And Allah is ever Knowing and Wise. (Qur’an 4:92)

Now, I’m sure these guys don’t have any Muslim slaves so have they been consecutively fasting for two months as an expiation for their crimes? Have they given compensation to the Muslim families of their victims?

The verse above is interesting because it’s saying that even during times of war, if a believer is killed who happens to live among enemy’s territory, there is a penalty for it. So their whole rant about if a Muslim lives among the enemy, he is an infidel garbage is completely baseless.

Now, an extremist might say that the so called “Muslims” that they kill are not really Muslims so there is no penalty. That’s interesting because the Qur’an refutes that ideology:

O you who have believed, when you go forth [to fight] in the cause of Allah , investigate; and do not say to one who gives you [a greeting of] peace “You are not a believer,” aspiring for the goods of worldly life; for with Allah are many acquisitions. You [yourselves] were like that before; then Allah conferred His favor upon you, so investigate. Indeed Allah is ever, with what you do, Acquainted. (Qur’an 4:94)

This is what Tafsir Al-Jalalayn, one of the classical and most popular Qur’anic exegesis among Sunnis says about the above verse:

The following (Qur’an 4:94) was revealed when a group from among the Companions passed by a man from the Banū Sulaym driving his flock of sheep, and he offered them a greeting of peace. But they said, ‘He only greeted us dissimulating, out of fear’. So they killed him and took away his flock: O you who believe, when you are going forth, travelling in order to struggle, in the way of God, be discriminating (fa-tabayyanū; a variant reading has fa-tathabbatū, ‘ascertain’, here and further below); and do not say to him who offers you peace (read al-salām or al-salam), that is, the greeting, or [offers you] submission, declaring the profession of faith (shahāda), which is an indication of being a Muslim: ‘You are not a believer: you are only saying this to dissimulate for fear of your life and property’, so that you then end up killing him, desiring, seeking by this, the transient goods of the life of this world, that is, its enjoyment, in the way of spoils. With God are plenteous spoils, rendering you free of the need to kill such a person for his property. So you were formerly, when your lives and property were protected simply upon your professing the faith; but God has been gracious to you, making you known for your faith and uprightness. So be discriminating, lest you kill a believer and treat those entering the religion as you were treated [formerly]. Surely God is ever Aware of what you do, and will requite you for it.

As for killing non-combatant non-Muslims at times of war, then the Qur’an is also very explicitly clear:

Those who come to you, their hearts strained at [the prospect of] fighting you or fighting their own people. And if Allah had willed, He could have given them power over you, and they would have fought you. So if they remove themselves from you and do not fight you and offer you peace, then Allah has not made for you a cause [for fighting] against them. (Qur’an 4:90)

And also:

Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes – from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly. (Qur’an 60:8)

If you were to delve more into books of Quranic exegesis for the above verses, you would find much more information that refutes Muslim extremist claims. I haven’t even included the hadiths which also offers so much more information.