‘Abd-Allaah ibn al-Imaam Ahmad ibn Hanbal said; “I said to my father, ‘There are some people who say that the jinn do not enter the body of the epileptic.’ He said: ‘O my son, they are lying; the jinn could speak through this person.’” Commenting on this, Ibn Qudaamah said: “What he said is well known, because a person may suffer an epileptic seizure and speak in a language that no one understands, and his body may be beaten with blows that would fell a camel, but the epileptic does not feel them at all, and he is also unaware of the words he is saying. The epileptic and others may be dragged about, or the carpet on which he is sitting may be pulled, and utensils may be moved about from place to place, and other things may happen. Anyone who witnesses such a thing will know for sure that the one who is speaking through the person and moving these things is not human.” And he said, may Allaah have mercy on him: “There is no one among the imaams of the Muslims who denies that jinn may enter the body of the epileptic and others. Anyone who denies that and claims that Islam denies it is lying about Islam. There is nothing in the proofs of sharee’ah to show that it does not happen.”
So the fact that jinn may enter human bodies is proven in the Qur’aan and Sunnah, and by the consensus of Ahl al-Sunnah wa’l-Jamaa’ah, some of whose comments we have quoted above.