Al-Adab Al-Mufrad, Hadith 259 ⓘ
Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "Anyone who attributes words to me which I did not say should take his seat in the Fire. Anyone who gives his Muslim brother misguided advice when they consult him has betrayed them. If anyone gives a fatwa which is not firm, the wrong action of that rests on the one who gave the fatwa."
حَدَّثَنَا عَبْدُ اللهِ بْنُ يَزِيدَ قَالَ: حَدَّثَنِي سَعِيدُ بْنُ أَبِي أَيُّوبَ قَالَ: حَدَّثَنِي بَكْرُ بْنُ عَمْرٍو، عَنْ أَبِي عُثْمَانَ مُسْلِمِ بْنِ يَسَارٍ، عَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ النَّبِيُّ صلى الله عليه وسلم: مَنْ تَقَوَّلَ عَلَيَّ مَا لَمْ أَقُلْ، فَلْيَتَبَوَّأْ مَقْعَدَهُ مِنَ النَّارِ وَمَنِ اسْتَشَارَهُ أَخُوهُ الْمُسْلِمُ، فَأَشَارَ عَلَيْهِ بِغَيْرِ رُشْدٍ فَقَدْ خَانَهُ وَمَنْ أُفْتِيَ فُتْيَا بِغَيْرِ ثَبْتٍ، فَإِثْمُهُ عَلَى مَنْ أَفْتَاهُ.
also referenced under: Book 13, Hadith 4 (In-Book) & Book 13, Hadith 259 (English)