"Have they not pondered the Word?" means: the Quran. "Or has there come to them what did not come to their forefathers?" meaning: nothing has come to them except that which came to their forefathers.
﴿أفلم يدبروا القَوْل﴾ يَعْنِي: الْقُرْآنَ ﴿أَمْ جَاءَهُمْ مَا لم يَأْتِ آبَاءَهُم الْأَوَّلين﴾ أَيْ: لَمْ يَأْتِهِمْ إِلَّا مَا أَتَى آبَاءَهُم الْأَوَّلين.
