From Sahih Muslim (Hadith 2312):
Khaithama reported:While we were sitting in the company of 'Abdullah b. 'Umar there came in his steward. He (Ibn 'Umar) said: Have you supplied the provision to the slaves? He said: No. Upon this he said: Go and give (the provision) to them, for the Messenger of Allah (ﷺ) has said: This sin is enough for a man that he withholds the subsistence from one whose master he is
Reference: Muslim 2312