Supplication for the Khawarij, Praying for Them, and Burying Them

Question:
May Allah send blessings upon you. This questioner says: Honorable Shaykh, is it permissible to make du'a for the Khawarij who died in battle or otherwise? Is it permissible to pray the funeral prayer for those who died among them? And are they to be buried in Muslim cemeteries?

Answer:
There is scholarly disagreement regarding the ruling on the Khawarij. The majority hold that they are Muslims who have not exited Islam, but they are considered among the people of major sins; therefore, the funeral prayer is performed for them and du'a is made for them. The second opinion, held by a group of hadith scholars such as Imam al-Bukhari and others, is that they are disbelievers who have exited Islam. According to this view, the funeral prayer is not performed for them, and istighfar (seeking forgiveness) is not made for them. The issue comes down to the disagreement among scholars regarding their ruling. One who does not consider them disbelievers prays for them and keeps his distance from them, while one who considers them disbelievers keeps his distance from them.