"And We gave him Isaac and Jacob as a gift (nafilatan)" Al-Hasan said: meaning, a grant.
﴿وَوَهَبْنَا لَهُ إِسْحَاقَ وَيَعْقُوبَ نَافِلَةً﴾ قَالَ الْحسن: أَي: عَطِيَّة.