Qareen

A Qareen (قرين qarīn, literally meaning: 'constant companion') is a spiritual double of a human, either part of the human himself or a complementary creature in a parallel dimension. Due to its ghostly nature, the Qareen is classified among the Jinn-type creatures, although usually not actually a Jinni. The Qareen as an accompanying spirit should not be confused with the Qarinah, a female "childbed demon" in Middle Eastern traditions.

Quran
In the Quran, the concept of a Qareen is absent. The term, meaning "companion" appears a few times, but without any demonic associations. Hans Alexander Winkler noted that the Quranic reference to a Qareen refers to an earthly companion like a friend, who influences a Muslim to leave the Islamic community. Even the "satan" mentioned in 43:36 would refer to a human tempter (shaytan al ins), not a spiritual entity. It is only in the hadith that spiritual company is clearly associated with the term Qareen. Here, it refers to either a demon or angel. Only in later folklore is a Qareen considered a spiritual doppelganger of an individual human.

The term Qareen is mentioned in the following Quran verses without necessarily referring to any type of spiritual creature:

Sūrat az-Zukhruf: "And whosoever turns away from remembering and mentioning the Most Beneficent, we appoint for him a Satan to be a Qareen to him."

Sūrat as-Saffat: "A speaker among them will say, 'Indeed, I had a Qareen.'"

Sūrat an-Nisa: "And those who spend of their wealth to be seen by the people and believe not in Allah nor in the Last Day. And he to whom Satan is a Qareen - then evil is he as a Qareen."

Sūrat Qaf: "And his Qareen, will say, 'This is what is with me, prepared.'"

Interpretation
Several opinions exist on the exact nature of the Qareen. According to one opinion, the Qareen is actually a Shaitan, who entices a human with waswās ("evil suggestions"), but can become good in accordance with the human’s good deeds. However, it is uncertain whether or not a Qareen besides that of Muhammad can actually become good.

Another opinion holds that Qareen refers to any type of spirit accompanying humans. Here, the Qareen refers to demons, who give evil suggestions, but also to angels, who counsel towards good deeds.

Furthermore, the Qareen is depicted as the other self: a spirit integral to the person. A dissent between the inner Qareen and behavior may cause the same symptoms as Jinn-possession.

Other sources
The concept of a Qareen appears in pre-Islamic literature as well, and is reminiscent of the Greek daimones and the Christian guardian angel. In Pre-Islamic Arabian myth the Qareen is said to be able to inspire poets for their works.

How prevalent it is in folk belief varies by country. For example, it is more popular in Egypt than Sudan. It is possible the concept in Egypt has been influenced by the older concept of the ka. In some cases (such as that of holy men), the qarin or karin persists after a person has died. In Egypt, both Copts and Muslims believe in the qarin, and believe it may turn into a cat or dog at night. Amulets are used to guard against the qarin, especially if it is jealous. Pregnant women in Egypt used to visit a sheikha three months before birth to ask their counsel on ensuring their qarina does not harm their child. The prescribed rituals and amulets usually involve the number seven. Brides in Upper Egypt also wore amulets against their qarin.

Some record the belief from Ibn Hanbal that one has a "qarin of the jinn and a qarin of the angels".

Russian and Turkish Muslims believe the qarin is present in the womb with the person it's attached to.

One of the seven mu'allaqat—Arabic poems recognized as masterpieces during the pre-Islamic period—uses the word as a metaphor. To describe his tribe's excellence in battle, poet Amr bin Kulthum says that "every tribe has taken fear of us as a qarin (or 'constant companion')," meaning that their fear of Amr's tribe is always present. This goes further to show the origin of the word qareen, as described in the Arabic dictionary as a "companion".