Surah At-Tawbah 9:79

ٱلَّذِينَ يَلْمِزُونَ ٱلْمُطَّوِّعِينَ مِنَ ٱلْمُؤْمِنِينَ فِى ٱلصَّدَقَـٰتِ وَٱلَّذِينَ لَا يَجِدُونَ إِلَّا جُهْدَهُمْ فَيَسْخَرُونَ مِنْهُمْ ۙ سَخِرَ ٱللَّهُ مِنْهُمْ وَلَهُمْ عَذَابٌ أَلِيمٌ

Those who criticize the contributors among the believers concerning [their] charities and [criticize] the ones who find nothing [to spend] except their effort, so they ridicule them - Allāh will ridicule them, and they will have a painful punishment.

Translation: Saheeh International

Tafsir

When the verse concerning ‘voluntary alms’ Q. 975 was revealed a man came and gave a large amount as voluntary alms so the hypocrites said ‘He is merely showing off!’ Another man then came and gave a moderate measure of food and so they said ‘God has no need of this man’s charity!’ The following was then revealed …

Excerpt from Tafsir al-Jalalayn, commentary on 9:79, via Quran.com. The reader has the full commentary and 9 more tafsirs.