The Prophet [SAW] said: "A'udhu billahi minal-kufri wad-dain. (I seek refuge with Allah from Kufr and debt.)" A man said: "Are you equating debt with Kufr?" He said: "Yes." (Using translation from Nasāʾī 5474)
عَنِ النَّبِيِّ ﷺ أَنَّهُ قَالَ «أَعُوذُ بِاللَّهِ مِنَ الْكُفْرِ وَالدَّيْنِ» فَقَالَ رَجُلٌ يَا رَسُولَ اللَّهِ وَتَعْدِلُ الْكُفْرَ بِالدَّيْنِ؟ قَالَ «نَعَمْ»