Ibn Kathir (Abridged)
Hafiz Ibn KathirAllah describes the regret of the disbelievers when facing Him, and their disappointment at the commencement, along with theirsorrow for not performing good deeds and for their evil deeds
This is why Allah said, حَتَّى إِذَا جَآءَتْهُمُ السَّاعَةُ بَغْتَةً قَالُواْ يحَسْرَتَنَا عَلَى مَا فَرَّطْنَا فِيهَا(until all of a sudden, the Hour (signs of death) is upon them, and they say: "Alas for us that we gave no thought to it.") `It' here refers to either the life of this world, or the affairs of the Hereafter. Allah's statement, وَهُمْ يَحْمِلُونَ أَوْزَارَهُمْ عَلَى ظُهُورِهِمْ أَلاَ سَآءَ مَا يَزِرُونَ(while they will bear their burdens on their backs; and evil indeed are the burdens that they will bear!) Asbat said that As-Suddi said, "Upon entering his grave, every unjust person will meet a man with an ugly face, dark skin, awful odor, wearing dirty clothes, who will enter his grave with him.
When the unjust person sees him, he will say, `How ugly is your face!' He will reply, `So was your work, it was ugly.' The unjust person will say, `How foul is the odor coming from you!' He will reply, `Such was the case with your work, it stunk.' The unjust person will say, `How dirty are your clothes!' He will reply, `And your work too was dirty.' The unjust person will ask, `Who are you' He will reply, `I am your deeds.' So he will remain with the unjust person in his grave, and when he is resurrected on the Day of Resurrection, his companion will say to him, `In the life of the world, I used to carry you because you followed desire and lust. Today, you carry me.' So he will ride on the unjust person's back and lead him until he enters the Fire.
So Allah said, وَهُمْ يَحْمِلُونَ أَوْزَارَهُمْ عَلَى ظُهُورِهِمْ أَلاَ سَآءَ مَا يَزِرُونَ(while they will bear their burdens on their backs; and evil indeed are the burdens that they will bear!) 6:31" Allah's statement, وَمَا الْحَيَوةُ الدُّنْيَآ إِلاَّ لَعِبٌ وَلَهْوٌ(And the life of this world is nothing but play and amusement.) means, most of it is play and amusement, وَلَلدَّارُ الاٌّخِرَةُ خَيْرٌ لِّلَّذِينَ يَتَّقُونَ أَفَلاَ تَعْقِلُونَ(But far better is the abode of the Hereafter for those who have Taqwa. Will you not then understand)