Sahih al-Bukhari 6782
Sahih al-Bukhari · Book 86: Limits and Punishments set by Allah (Hudood) · The thief while stealing
Narrated Ibn `Abbas:
حَدَّثَنِي عَمْرُو بْنُ عَلِيٍّ ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ دَاوُدَ ، حَدَّثَنَا فُضَيْلُ بْنُ غَزْوَانَ ، عَنْ عِكْرِمَةَ ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ يَزْنِي الزَّانِي حِينَ يَزْنِي وَهْوَ مُؤْمِنٌ، وَلاَ يَسْرِقُ حِينَ يَسْرِقُ وَهْوَ مُؤْمِنٌ " .
The Prophet (ﷺ) said, "When (a person) an adulterer commits illegal sexual intercourse then he is not a believer at the time he is doing it; and when somebody steals, then he is not a believer at the time he is stealing."