"Until when We open for them a gate of severe punishment," meaning: on the day of Badr, they were killed by the sword. "Lo! They are in despair therein," meaning: they despaired of every good.
Surat al-Mu'minun from (verse 78 to verse 89).
﴿حَتَّى إِذَا فَتَحْنَا عَلَيْهِمْ بَابًا ذَا عَذَاب شَدِيد﴾ يَعْنِي: يَوْمَ بَدْرٍ قُتِلُوا بِالسَّيْفِ ﴿إِذا هم فِيهِ مبلسون﴾ يئسوا من كل خير.
سُورَة الْمُؤْمِنُونَ من (آيَة ٧٨ آيَة ٨٩).