Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) narrates this saying of the Prophet (peace and blessings be upon him): "The best of your young people are those who resemble the elderly, and the worst of your elderly are those who resemble the young."
Imam Abu Ya'la and Imam al-Tabarani recorded this narration; its chain contains narrators whom I do not know.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزهد / 17956
Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "The best of your young people are those who resemble your middle-aged people, and the worst of your middle-aged people are those who resemble your young people."
Imam al-Tabarani and Imam al-Bazzar recorded this narration; the chains of both contain a narrator, al-Hasan bin Abi Ja'far, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزهد / 17957
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه البزار فى المسند (3219) ، أخرجه المعجم الأوسط للطبراني برقم: 5900»
Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Indeed, Allah Almighty dislikes a seventy-year-old who adopts the appearance of a twenty-year-old in his walk and his look."
Imam al-Tabarani recorded this narration in al-Mu'jam al-Awsat, and he said: It is narrated from the Prophet (peace and blessings be upon him) only with this chain. Its chain contains a narrator, Musa bin Muhammad bin Ibrahim bin al-Harith, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزهد / 17958