Allah (S.w.T.) says in Surah at-Tawba,
“They who taunt those of the faithful who give their alms freely, and those who give to the extent of their earnings and scoff at them; Allah will pay them back their scoffings and they shall have a painful chastisement.” (Surah at-Tawba 9: 79)
According to traditions the circumstances of revelation (Shān al-Nuzūl) of this ayat are as follows: During the Battle of Tabuk the Holy Prophet (S) announced that people should donate as much as they can to cover the cost of this Battle. The affluent people donated large amounts and the poor gave whatever little they could. A companion by the name of Abu Aqīl Ansari brought 1.75 sīr of dates and said, “I have laboured from last night till morning and received 3.5 sīr of dates. Half I left for my family and the other half for Allah.” The hypocrites began to make fun of both the types of people and began to find faults with them. For those who donated more, they said that they have given such large amounts to show off their wealth and for those who could contribute little, they said: They want to be included among the philanthropist, or they wanted people to consider them at the time of giving charity.