وَوَهَبْنَا لَهُ إِسْحَقَ وَيَعْقُوبَ نَافِلَةًAnd We bestowed upon him Ishaq, and Ya`qub Nafilatan.Ata' and Mujahid said,"Nafilatan means as a gift."Ibn Abbas, Qatadah and Al-Hakam bin `]Uyaynah said,"The gift of a son who has a son,"meaning that Yaqub was the son of Ishaq, as Allah says:فَبَشَّرْنَـهَا بِإِسْحَـقَ وَمِن وَرَاءِ إِسْحَـقَ يَعْقُوبَBut We gave her glad tidings of Ishaq, and after Ishaq, of Yaqub. (11:71)Abdur-Rahman bin Zayd bin Aslam said,"He asked for one (son), and said, رَبِّ هَبْ لِى مِنَ الصَّـلِحِينِ"My Lord! Grant me from the righteous." (37:100) So Allah gave him Ishaq, and gave him Yaqub in addition. وَكُلًّ جَعَلْنَا صَالِحِينَEach one We made righteous.means, both of them were good and righteous people.