It is reported that Bakr b. ʿAbdillāh Al-Muzanī – Allāh have mercy on him – said:
When you see someone older than you, say: he has preceded me in īmān and righteous actions so he is better than me; and when you see someone younger than you, say: I have preceded him in sinning and disobedience so he is better than me. And when you see your brothers honouring and revering you, say: this is a virtue they have attained; and when you see them falling short (in their treatment of you) say: this is [because of] a sin I committed.
Ibn Al-Jawzī, Ṣifatu Al-Ṣafwah, article 505: Bakr b. ʿAbdillāh Al-Muzanī.