Aamir bin Sa’d bin Abi Waqqas narrates from his father that the Prophet Muhammad (peace be upon him) said: "The greatest crime among the Muslims is of the person who inquires about something that has not been declared unlawful, and then because of his inquiry, it is declared unlawful for the Muslims."
Hadith Referenceصحیح ابن حبان / كتاب العلم / 110
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الصحيحة» (3276): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط البخاري.