Riyad as-Salihin 359
Anas bin Malik (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "If a young man honours an older person on account of his age, Allah appoints someone to show reverence to him in his old age" [At-Tirmidhi, who classified it as Hadith Gharib] .
وعن أنس رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم ‏:‏‏
"‏ما أكرم شاب شيخًا لسنه إلى قيض الله له من يكرمه عند سنه‏"‏ ‏(‏‏(‏رواه الترمذي وقال‏:‏ حديث غريب‏)‏‏)‏‏.‏