Do not belittle any good thing
And the example given is deliberately small.
لاَ تَحْقِرَنَّ مِنَ الْمَعْرُوفِ شَيْئًا وَلَوْ أَنْ تَلْقَى أَخَاكَ بِوَجْهٍ طَلْقٍ
Do not belittle any good deed, even meeting your brother with a cheerful face.
The full narration
Abu Dharr reported:Allah's Apostle (ﷺ) said to me: Don't consider anything insignificant out of good things even if it is that you meet your brother with a cheerful countenance
Source
Ṣaḥīḥ Muslim · 6690
Ṣaḥīḥ
- Agreed upon as authentic (al-Bukhārī / Muslim)