Imam Nawawi's 40 hadith, Chapter: An-Nawawi's 40 Hadith

that the Messenger of Allah, sallallahu alayhi wasallam, said: "Verily Allah the Exalted is pure. He does not accept but that which is pure. Allah commands the believers with what He commanded the Messengers. Allah the Almighty has said: "O you Messengers! Eat of the good things and act righteously" [23:51-53]. And Allah the Almighty also said: "O you who believe! Eat of the good things that We have provided you with" [2:167-172]. Then he (the Prophet) mentioned (the case of) the man who, having journeyed far, is dishevelled and dusty and who stretches out his hands to the sky (saying): "O Lord! O Lord!" (while) his food was unlawful, his drink was unlawful, his clothing was unlawful, and he is nourished with unlawful things, so how can he be answered?" [Muslim]