Sahih Muslim Book 5, Hadith Number 2222.

Chapter : The Labourer should give charity out of his wages and it is severely forbidden to belittle one who contributes less.

Jarir b. ‘Abdullah reported: People came to the Messenger of Allah (may peace be upon him) and they were dressed in woollen clothes. He (the Holy Prophet) saw their dismal state, as they were suffering from want and the rest of the Hadith is the same.