At-Tawbah 9:79

Allatheena yalmizoona almuttawwiAAeenamina almu/mineena fee assadaqati wallatheenala yajidoona illa juhdahum fayaskharoona minhumsakhira Allahu minhum walahum AAathabun aleem

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.

(Among the hypocrites, there are) those who taunt the believers who voluntarily give alms and have nothing but their hard earnings; still they mock at such people. Allah mocks at them, and for them there is a painful punishment.