Asking material help from others is permissible but presuming that prophets/pious posses supernatural/mystical powers and can provide metaphysical help(Ghaibi madad) is "shirk / comparison".
Some people see no problem in asking a doctor for help but say asking saint for help is "shirk". The reason they say is doctor offers 'Physical Help' and asking a saint to grant health is asking ‘Metaphysical Help'(Ghaibi madad)and asking metaphysical help is shirk. This type of classification can nowhere be found in Quran and Hadith.People claiming to follow just Quran and Hadith should not distinguish between the two and even asking a doctor for help should be shirk. Various verses of Quran and Ahadith prove that pious people offered metaphysical help. (See Section 4 for Ahadith Hazrath Ali (RA) getting his eyes cured just with the touch of a hand and Hazrath Abu Huraira(RA) getting good memory are all examples of‘Metaphysical help')
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