Sahih Muslim #6116 · The Book of Virtues

Sahih MuslimAmir b. Sa'd reported on the authority of his father that Allah's Messenger
Sahih Muslim · Book 43 · The Book of Virtues
Sahih Muslim · كتاب 43 · كتاب الفضائل
The greatest sinner amongst the Muslims is one who asked about a thing (from Allah's Apostle) which had not been forbidden for the Muslims and it was forbidden for them because of his persistently asking about it.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عَامِرِ بْنِ، سَعْدٍ عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ إِنَّ أَعْظَمَ الْمُسْلِمِينَ فِي الْمُسْلِمِينَ جُرْمًا مَنْ سَأَلَ عَنْ شَىْءٍ لَمْ يُحَرَّمْ عَلَى الْمُسْلِمِينَ فَحُرِّمَ عَلَيْهِمْ مِنْ أَجْلِ مَسْأَلَتِهِ ‏"‏ ‏.‏
Reference : Sahih Muslim 6116In-book reference : Book 43, Hadith 174