"We will surely assign them (la-nubawwi'annahum)," meaning: We will surely cause them to dwell, "from Paradise in chambers... Excellent is the reward of the workers," meaning: the excellent recompense for those who performed deeds in the world; that is: Paradise.
﴿لنبوئنهم﴾ أَيْ: لَنُسْكِنَنَّهُمْ ﴿مِنَ الْجَنَّةِ غُرَفًا … نعم أجر العاملين﴾ نِعْمَ ثَوَابُ الْعَامِلِينَ فِي الدُّنْيَا؛ يَعْنِي: الْجنَّة
