Sihr is divided in two types:-
One is through suggestion, illusionists, mediums, tricks, deception and the speed of the hand illusion. Second is the use of evil spirits, sorcery, witchcraft, voodoo, which has an effects on man as a whole.
Evidences from the Qur'an:-
Allah (SWT) says:
“And they followed [instead] what the devils had recited during the reign of Sulaiman (AS) but it was not Sulaiman who disbelieved, but it was the devils who disbelieved; Teaching people magic and that which was revealed to the two angels at Babylon, Harut and Marut. But the two angels do not teach anyone unless they say, “We are a trial, so do not disbelieve [by practicing magic].” And [yet] they learn from them that by which they cause separation between a man and his wife. But they do not harm anyone through it except by permission of Allah. And the people learn what harms them and does not benefit them. But the Children of Israel certainly knew that whoever purchased the magic would not have in the Hereafter any share. And wretched is that for which they sold themselves, if they only knew.” (Al-Baqarah: 102)
"And they said: 'No matter what sign you bring us with which to bewitch us, we will not be believers in you.'” (Al-A’raf: 132)
"And when they had thrown, Moses said: 'What you have brought is [only] magic. Indeed, Allah will expose its worthlessness. Indeed, Allah does not amend the work of corrupters.'" (Yunus: 81)
"Say: 'I seek refuge in the Lord of daybreak. From the evil of that which He created. And from the evil of darkness when it settles. And from the evil of the blowers in knots. And from the evil of an envier when he envies.'" (Al-Falaq: 1-5)
Narrated from Abdullah ibn Umar (RAA); Two men came from the East and addressed the people who wondered at their eloquent speech. On that Allah's Messenger ﷺ said: “Some eloquent speech is as effective as Magic.” (Bukhari)
Evidence from the Sunnah :
'Aisha (RA) reported:"A man known as Labid Ibn al-A'sam from the tribe of Band Zurayq performed sihr on Allah's Messenger ﷺ till Allah's Messenger ﷺstarted imagining that he had done something which he had not really done. One day or one night while he was with me, he invoked Allah ('Azza wa Jalla) for a long period, and then said, 'O 'Aisha! Do you know that Allah has instructed me concerning the matter I have asked him about? Two men came to me and one of them sat near my head and the other near my feet. One of them said to his companion, 'What is the pains this man?' The other replied, 'He is under the effect of Mtbob'. The first one asked, 'Who did it?' The other replied, 'Labid Ibn Al-A'sam.' The first one asked, 'What material did he use?' The other replied, 'A comb and the hairs stuck to it and the pollen of a male date palm.' The first one asked, 'Where is that?' The other replied, '(That is) in the well of Daman!" So Allah's Messenger ﷺ, along with some of his companions went there and returned saying, 'O 'Aisha, the colour of its water is like the infusion of henna leaves. The tops of the date-palm trees near it are like the heads of the devils.' I asked, 'O Allah's Messenger? Why don't you show it (to the people)?' He said, 'Since Allah ('Azza wa Jalla) has cured me, I would not like to let evil spread among people.' Then he ordered that the well be filled up with earth." Reported by Al-Bukhari (10/222, in Fath Al-Bari) and Muslim (14/174, in Sharh An-Nawawi), the Book of Salam, Chapter on Sihr.
Abu Hurayra (RA) reported: "The Prophet c said: 'Avoid the seven serious sins (As-sa' Al-Mubiqat)" People asked, 'What are they?' The Prophet Peace and Blessing upon him) replied, 'Shirk (polytheism), sihr (sorcery), unlawful killing of a person, living on money from usury, usurping an orphan's wealth, retreat at the time of Jihad, and accusing innocent married women of fornication'" Al-Bukhari (in FathAl-Bari 5/393) and Muslim (in Sharh An-Nawawi 2/83).
On the basis of the above hadith, the Prophet ﷺ warned that sihr must be avoided as it is one of the most serious sins, and this is proof enough that it exists.
There are more hadith and ayat concerning this subject.
Signs of sihr
There are certain signs and symptoms that show in a person who has been bewitched. Signs and symptoms will be individual to the person, and may not necessarily be obvious. Sometimes it may not be very clear that the person has been bewitched, especially if they are close to Allah azza wa jal. The effects of sihr may not take control of them in the same way or to the same extent it might do to someone who is not particularly mindful of Allah, and generally will not be obvious to untrained eye. The signs of sihr may be similar or exactly like the signs of ‘ayn and hasad, and resemble the signs of a person possessed by a jinn i.e. with the physical and mental illnesses. The only time the difference can be determined is during the ruqyah.
The Effects of Sihr
Sihr (magic) has, by the will of Allah azza wa jal, the capacity to affect many aspects of people’s lives, depending on what the intent behind the magic is. Some examples of the outcomes of sihr can be found below;
To separate husband and wife
To supress a man’s desire for his wife and the wife’s desire for her husband
To cause miscarriage, blocking the fallopian tubes, and disabling the ovaries
Constant bleeding for women and the opposite where there is no menstrual cycle
To affect a person’s fertility
To make a man love a woman so he marries her, and the same could be done to a woman
To encourages a person to fall into adultery and immorality, whether the motive of the magician is for love, revenge, or to destroy a person’s reputation
To separate families and destroy them
To torment a person with insomnia, loss of appetite, daydreaming, tightness in chest, sadness and depression, a feeling of pain the body etc.
To use magic for murder by various methods, e.g. arson in the home, where the jinn carry it out themselves in a physical form or by taking possession of the person
Magic is used in robberies and extortion, deception such as scamming a person of his home, gold, money or bank details without their will
Sihr is used to affect businesses and trade, from small levels to big
Magic can be used cause all types of sickness and illnesses, even diseases that doctors cannot define
Magic can be used in the kidnapping of people
To cause illusions i.e. tricks of the eyes so they people do not see what is really happening, like what happened in the time of Musa (peace be upon him)
In nature to destroy a farm land by stopping rain falling in certain areas, and destroying wells
In a person’s character, habits, ethics and transactions
In harming animals or insects or using them for sihr