It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Recite the Qur'an with its proper vowelling (correctly and properly), for whoever recites the Qur'an and recites it with its proper vowelling, for him there are ten good deeds for every letter, an expiation of ten bad deeds, and an elevation of ten ranks."
Hadith Referenceالمعجم الأوسط / باب الميم / 7574
Hadith Gradingمحدثین:إسناده ضعيف جدًّا، فيه نهشل بن سعيد متروك
Hadith Takhrij«قال الهيثمي: فيه نهشل وهو متروك «مجمع الزوائد ومنبع الفوائد، ج 7، ص 163»»