From the route of Abu Hurayrah, may Allah accept his deeds, who said, The Messenger of Allah, sallallahu ^alayhi wa sallam, said:
<<Allah is Attributed with genuine Attributes and only accepts what is lawful. Allah has ordered the believers with what He ordered the Messengers; so Allah said: يَا أَيُّهَا الرُّسُلُ كُلُوا مِنَ الطَّيِّبَاتِ وَاعْمَلُوا صَالِحًا (It means: [O Messengers, eat what is lawful and do the good deeds.]) And Allah said: يَا أَيُّهَا الَّذِينَ آمَنُواْ كُلُواْ مِن طَيِّبَاتِ مَا رَزَقْنَاكُمْ (It means: [O believers eat from the lawful sustenance that We provided for you.])
Then the Prophet mentioned the man who travels extensively to perform obedience, and who is dusty with untidy hair, putting his hands up to the sky making supplication and saying, ‘O Lord, O Lord’, while his food is unlawful, his drink is unlawful, his clothing is unlawful and was nourished unlawfully. How could such a person’s supplication be answered?>>
Narrated by Muslim.