Jinn dwelling in humans
Question

Can a jinn enter the body of a human?
Praise be to Allah.Imam Shaykh al-Islam said in his Fatawa after some introductory comments:
… For this reason, a group of the Mu’tazilah, such as al-Jabbaa’i, Abu Bakr al-Raazi and others, denied that the jinn enter the body of the epileptic, although they do not deny the existence of the jinn, because that is not as clearly mentioned in the reports narrated from the Messenger   (peace and blessings of Allah be upon him) as their existence is mentioned. They were mistaken in this matter. Hence al-Ash’ari mentioned in Maqaalaat Ahl al-Sunnah wa’l-Jamaa’ah that they [Ahl al-Sunnah] believe that the jinn may enter the body of the epileptic, as Allah says (interpretation of the meaning):
‘Those who eat Ribawill not stand (on the Day of Resurrection) except like the standing of a person beaten by Shaytaan (Satan) leading him to insanity…’
[al-Baqarah 2:275]
 ‘Abd-Allah ibn al-Imam Ahmad said: I told my father that some people claim that the jinn do not enter the body of a human. He said, O my son, they are lying, for a jinn may speak with the tongue of a person who is lying on his sick-bed. (Majmoo’ Fatawa Shaykh al-Islam Ibn Taymiyah, 19/12). He also said (may Allah have mercy on him), in vol. 24 of his Fatawa (p. 276, 277):
“The existence of the jinn is proven by the Book of Allah and the Sunnah of His Messenger (peace and blessings of Allah be upon him), and by the consensus of the salaf and scholars of this ummah. Similarly, the fact that the jinn can enter human bodies is also proven by the consensus of the imams of Ahl al-Sunnah wa’l-Jamaa’ah. Allah says (interpretation of the meaning):
‘Those who eat Ribawill not stand (on the Day of Resurrection) except like the standing of a person beaten by Shaytaan (Satan) leading him to insanity…’
[al-Baqarah 2:275]
In al-Saheeh it is narrated that the Prophet (peace and blessings of Allah be upon him) said: ‘The Shaytaan flows through the son of Adam as his blood flows…
There is no one among the imams of the Muslims who denies that the jinn enter the body of the epileptic. Whoever denies that and claims that Islam denies that is telling lies about the sharee’ah, for there is no evidence in sharee’ah to say that this is not the case…”