Sahih al-Bukhari, Book 96, Hadith 20 (In-Book) ⓘ

Narrated Sa`d bin Abi Waqqas: The Prophet said, "The most sinful person among the Muslims is the one who asked about something which had not been prohibited, but was prohibited because of his asking."

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يَزِيدَ الْمُقْرِئُ، حَدَّثَنَا سَعِيدٌ، حَدَّثَنِي عُقَيْلٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عَامِرِ بْنِ سَعْدِ بْنِ أَبِي وَقَّاصٍ، عَنْ أَبِيهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏ "‏ إِنَّ أَعْظَمَ الْمُسْلِمِينَ جُرْمًا مَنْ سَأَلَ عَنْ شَىْءٍ لَمْ يُحَرَّمْ، فَحُرِّمَ مِنْ أَجْلِ مَسْأَلَتِهِ ‏" ‏‏.‏