Sayyiduna Hudhayfah (may Allah be pleased with him) said: Three types of people can give fatwa: the Imam, or the ruler of the government, or the person who is knowledgeable about the abrogating and abrogated verses of the Qur'an. The people asked: Who can such a person be? He said: Either Sayyiduna Umar ibn al-Khattab (may Allah be pleased with him), or a foolish ignoramus who takes it upon himself.
Hadith Referenceسنن دارمي / مقدمه / 177
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده ضعيف لانقطاعه محمد بن سيرين لم يدرك حذيفة، [مكتبه الشامله نمبر: 177]
Hadith Takhrijاس روایت کی سند ضعیف ہے، لیکن اثر کی نسبت صحیح ہے۔ دیکھئے: [الفقيه 1194] ، [جامع بيان العلم 2214، 2217]