‘Abdullah ibn ‘Amr ibn al-‘As reported that it reached him that the Prophet, may Allah bless him and grant him peace, said, “Anyone who does not show mercy to our children nor acknowledge the right of our old people is not one of us.”
حَدَّثَنَا عَلِيٌّ، قَالَ‏:‏ حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا ابْنُ أَبِي جُرَيْجٍ، عَنْ عُبَيْدِ اللهِ بْنِ عَامِرٍ، عَنْ عَبْدِ اللهِ بْنِ عَمْرِو بْنِ الْعَاصِ، يَبْلُغُ بِهِ النَّبِيَّ صلى الله عليه وسلم، قَالَ‏:‏ مَنْ لَمْ يَرْحَمْ صَغِيرَنَا، وَيَعْرِفْ حَقَّ كَبِيرِنَا، فَلَيْسَ مِنَّا‏.‏
Reference : Al-Adab Al-Mufrad 354
In-book reference : Book 18, Hadith 2
English translation : Book 18, Hadith 354