The Prophet ﷺ said, "Whoever does not show mercy to our young and acknowledge the right of our elders is not one of us."
عن النبي ﷺ قال: من لم يرحم صغيرنا، ويعرف حق كبيرنا فليس منا.
Abu Dawud (4943), Ahmad (7073), Bukhari in Adab al-Mufrad (354), and Hakim (1/62) all narrated it from the hadith of Sufyan bin Uyayna, who said, Ibn Abu Najeeh narrated to us, from Ubaydullah bin Amir, from Abdullah bin Amr, and he mentioned it.Its isnad is hasan because of Ubaydullah bin Amir, whom Ibn Main declared trustworthy, as found in the History of Darimi (469). As for Hakim, he said, "Sahih according to the criteria of Muslim, for he relied on Abdullah bin Amir Al-Yahsabi, though the two of them did not narrate it." This contains an error, for he is not Abdullah bin Amir Al-Yahsabi, the one whom Muslim narrated for, but rather he is Ubaydullah bin Amir, as shown in the chain of Ahmad and in Adab al-Mufrad of Bukhari. Ubaydullah bin Amir is the Meccan, one of the narrators used only by Abu Dawud.