Surah al-Mulk was revealed like the rest of the surah in the Holy Qur’an separately, and for this reason the reasons for the revelation of the verses in the same surah are different. Their saying, so that the Messenger, may God’s prayers and peace be upon him, would not hear them, and that is why the Almighty’s saying was revealed to them: Or double in his personality when dealing with God Almighty, and that is why the basis of actions in Islam is intentions, from the virtues of Surah Al-Mulk. It has a special virtue in addition to that, so Surah Al-Mulk was one of these Surah that are mentioned in its great merit. If he is from the people of Disobedience and sins, and it was reported from the Messenger - may God’s prayers and peace be upon him - that whoever recites it every night has a fortress and a barrier from the torment of the grave, and that is why the Companions - may God be pleased with them - called it during the era of the Messenger - may God bless him and grant him peace.
And peace is a barrier, because it prevents its owner from the torment of the grave, and it is also called Surah Al-Mulk, the Protective Savior.