Surah Al-An'aam, Verse 31
قَدْ خَسِرَ ٱلَّذِينَ كَذَّبُوا۟ بِلِقَآءِ ٱللَّهِ ۖ حَتَّىٰٓ إِذَا جَآءَتْهُمُ ٱلسَّاعَةُ بَغْتَةًۭ قَالُوا۟ يَٰحَسْرَتَنَا عَلَىٰ مَا فَرَّطْنَا فِيهَا وَهُمْ يَحْمِلُونَ أَوْزَارَهُمْ عَلَىٰ ظُهُورِهِمْ ۚ أَلَا سَآءَ مَا يَزِرُونَ
Translation — Sahih International
Those will have lost who deny the meeting with Allah, until when the Hour [of resurrection] comes upon them unexpectedly, they will say, "Oh, [how great is] our regret over what we neglected concerning it," while they bear their burdens on their backs. Unquestionably, evil is that which they bear.
Source
Kur'an-ı Kerim, En'âm Suresi 6:31
https://kuran.diyanet.gov.tr/mushaf/kuran-meal-2/6-suresi-31-ayet