Ibn 'Umar said, "Allah has called them the 'dutiful' (al-Abrar) because they are dutiful (birr) to their parents and children. Just as you have a duty which you owe your parent, so you have a duty which you owe your child."  

إِنَّمَا سَمَّاهُمُ اللَّهُ أَبْرَارًا لأَنَّهُمْ بَرُّوا الْآبَاءَ وَالأَبْنَاءَ كَمَا أَنَّ لِوَالِدِكَ عَلَيْكَ حَقًّا كَذَلِكَ لِوَلَدِكَ عَلَيْكَ حَقٌّ