It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that "al-kanud" (the ungrateful) was mentioned before the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Al-kanud is the one who eats alone, withholds his help, and beats his slave."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7927