It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said: “The adulterer, at the time he is committing adultery, is not a believer; (the wine drinker) at the time he is drinking, is not a believer; the thief, at the time he is stealing, is not a believer; the plunderer, at the time he is plundering with the people looking on, is not a believer.”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عِيسَى بْنُ حَمَّادٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ عُقَيْلٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ الْحَارِثِ بْنِ هِشَامٍ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ " لاَ يَزْنِي الزَّانِي حِينَ يَزْنِي وَهُوَ مُؤْمِنٌ وَلاَ يَشْرَبُ الْخَمْرَ حِينَ يَشْرَبُهَا وَهُوَ مُؤْمِنٌ وَلاَ يَسْرِقُ السَّارِقُ حِينَ يَسْرِقُ وَهُوَ مُؤْمِنٌ وَلاَ يَنْتَهِبُ نُهْبَةً يَرْفَعُ النَّاسُ إِلَيْهِ أَبْصَارَهُمْ حِينَ يَنْتَهِبُهَا وَهُوَ مُؤْمِنٌ " .
sunnah.com