Sahih al-Bukhari, Book 34, Hadith 36 (In-Book) ⓘ
Narrated Abu Hurairah (ra): The Prophet said "Certainly a time will come when people will not bother to know from where they earned the money, by lawful means or unlawful means." (See Hadith no. 2050)
حَدَّثَنَا آدَمُ، حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، حَدَّثَنَا سَعِيدٌ الْمَقْبُرِيُّ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لَيَأْتِيَنَّ عَلَى النَّاسِ زَمَانٌ لاَ يُبَالِي الْمَرْءُ بِمَا أَخَذَ الْمَالَ، أَمِنْ حَلاَلٍ أَمْ مِنْ حَرَامٍ " .
also referenced under: Hadith 2083 (DarusSalam) & Volume 3, Book 34, Hadith 296 (USC-MSA)