In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Shaikh Uthaymeen [rahimahullaah] was asked about a people who hit themselves with metal objects and weapons, and it does not have any effect on them [i.e. they are not injured], and they claim that they are Awliyaa of Allaah:
The Shaikh responded: Just because these people hit themselves with metal objects or other things- and it does not have any effect on them- is neither a proof that they are truthful nor that they are Awliyaa of Allaah, nor that this is a miracle of theirs; rather this deed of theirs is a type of magic by way of which they deceive the eyes of the people. Magic can occur through this and other ways. When the Pharaoh’s magicians threw their ropes and sticks by way of their magical tricks, it appeared to Moosaa [alayhis salaam] as if they moved fast and that they were snakes, just as Allaah said: [سَحَرُوٓاْ أَعۡيُنَ ٱلنَّاسِ وَٱسۡتَرۡهَبُوهُمۡ وَجَآءُو بِسِحۡرٍ عَظِيمٍ- They bewitched the eyes of the people, and struck terror into them, and they displayed a great magic]. [Surah Al-A’raaf. Aayah 116]
There is no doubt that what they did was a type of magic and it was not a miracle. Therefore, know – may Allaah have mercy upon you – that miracles do not occur except at the hands of Allaah’s true Awliyaa – those who truly fear Allaah and are steadfast upon the religion ordained by Allaah, and Allaah described them in His statement:
أَلَآ إِنَّ أَوۡلِيَآءَ ٱللَّهِ لَا خَوۡفٌ عَلَيۡهِمۡ وَلَا هُمۡ يَحۡزَنُونَ
ٱلَّذِينَ ءَامَنُواْ وَڪَانُواْ يَتَّقُونَ
No doubt! Verily, the Auliya’ of Allah [i.e. those who believe in the Oneness of Allah and fear Allah much (abstain from all kinds of sins and evil deeds which he has forbidden), and love Allah much (perform all kinds of good deeds which He has ordained)], no fear shall come upon them nor shall they grieve, – those who believed [in the Oneness of Allah – Islamic Monotheism), and used to fear Allah much (by abstaining from evil deeds and sins and by doing righteous deeds]. [Surah Yunus. Aayaat 62-63]
Therefore, not everyone who claims to be a Waliy of Allaah is truly a Waliy of Allaah, otherwise everyone would make such a claim; rather a claimant is judged by His deeds, so if his deeds are based on Eemaan and Taqwaa, then indeed he is a Waliy. Merely claiming that he is a Waliy is something that cannot be attributed to true fear of Allaah [The Mighty and Majestic], because indeed Allaah [The Most High] Said: [ فَلَا تُزَكُّوٓاْ أَنفُسَكُمۡۖ هُوَ أَعۡلَمُ بِمَنِ ٱتَّقَىٰ – So ascribe not purity to yourselves. He [Allaah] knows best him who fears Allaah and keep his duty to Him. [Surah An-Najm. Aayah 32]
Therefore, if a person claims that he is a Waliy, then indeed he has praised himself and fallen into an act of disobedience to Allaah, and this is in opposition to Taqwah. And based on this, the true Awliyaa of Allaah do not praise themselves, rather they believe in Allaah, fear Allaah and obey Allaah in a perfect manner. Neither do they beguile nor deceive the people with the likes of these claims and thus misguide them from the path of Allaah.
[An Excerpt from ‘Fataawaa Fadheelah Ash-Shaikh Muhammad Ibn Saaleh Al-Uthaymeen Fil Aqeedah. Vol 2. Pages 855-856. Slightly paraphrased]