Yahya on Positivity: If you cannot benefit, at least do not harm

Abu al-Layth al-Samarqandi reported: Yahya ibn Mu’adh, may Allah have mercy on him, said, “If you cannot benefit, then do not harm. If you cannot bring joy, then do not bring distress. If you cannot praise, then do not blame.”

Source: Tanbīh al-Ghāfilīn 1/165

عَنْ أبي الليث السمرقندي عَنْ يَحْيَى بْنِ مُعَاذٍ الرَّازِيِّ قَالَ رحمه الله إِنْ لَمْ تَنْفَعْهُ فَلَا تَضُرُّهُ وَإِنْ لَمْ تَسُرُّهُ فَلَا تَغُمُّهُ وَإِنْ لَمْ تَمْدَحْهُ فَلَا تَذُمَّهُ

1/165 تنبيه الغافلين