Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah ﷺ said, "O people! Allah is Pure and, therefore, accepts only that which is pure. Allah has commanded the believers as He has commanded His Messengers by saying: 'O Messengers! Eat of the good things, and do good deeds.' (23:51) And He said: 'O you who believe (in the Oneness of Allah - Islamic Monotheism)! Eat of the lawful things that We have provided you..."' (2:172). Then he ﷺ made a mention of the person who travels for a long period of time, his hair are dishevelled and covered with dust. He lifts his hand towards the sky and thus makes the supplication: 'My Rubb! My Rubb!' But his food is unlawful, his drink is unlawful, his clothes are unlawful and his nourishment is unlawful, how can, then his supplication be accepted?"

[Muslim].

وعن أبي هريرة رضي الله عنه قال: قال رسول الله ﷺ :
"يا أيها الناس إن الله طيب لا يقبل إلا طيباً، وإن الله أمر المؤمنين بما أمر به المرسلين، فقال تعالى: {يا أيها الرسل كلوا من الطيباب واعلموا صالحاً}، وقال تعالى: {يا أيها الذين آمنوا كلوا من طيبات ما رزقناكم} ثم ذكر الرجل يطيل السفر أشعث أغبر يمد يديه إلى السماء : يا رب يارب، ومطعمه حرام، ومشربه حرام، وملبسه حرام، وغذي بالحرام فأنى يستجاب لذلك!؟" ((رواه مسلم)).