"Then there succeeded them a generation," Qatadah said, meaning: the Jews. "Who neglected prayer and pursued desires; so they will meet Ghayy." The interpretation of Ibn Mas'ud of (Ghayy) is: a valley in Hell. The interpretation of (al-khalaf) has already passed in Surah al-A'raf.
﴿فخلف من بعدهمْ خلف﴾ قَالَ قَتَادَةُ يَعْنِي: اليَهُودَ ﴿أَضَاعُوا الصَّلاةَ وَاتَّبَعُوا الشَّهَوَاتِ فَسَوْفَ يَلْقَوْنَ غيا﴾ تَفْسِير ابْن مَسْعُود (غيا): وَادٍ فِي جَهَنَّمَ، وَقَدْ مَضَى تَفْسِيرُ (الْخَلْفِ) فِي سُورَةِ الْأَعْرَافِ