Earning that which is permissible and avoiding that which is doubtful let alone prohibited should be the concern and fixation of every Muslim. This is because what you consume has an effect on the body.
“Every flesh produced on account of unlawful gains, the Fire is worthier of.”
(Tabaraany in his Al-Mu’jam Al-Ss-Ssagheer 625)
It also has a massive effect on the acceptance of supplications. Anyone who raises his hands to Allaah would hope that Allaah will accept his prayer and grant him his request, especially when he needs Him, but nonetheless, the obstacle to having supplications accepted is to consume wear haram and drink that which is prohibited. In the hadeeth, the Prophet ﷺ directed instructions to Sa‘d,
“Sa‘d! Make your food permissible and your prayers will be answered.”
(Tabaraany in his Al-Mu’jam Al-Awssatt 1015)
Similarly, the cause for the acceptance of prayers is clear, “disheveled and dusty,” meaning being humbled before his Lord; “on a long journey,” the journey is a possible factor for the acceptance of prayers; and the prayer of a traveler is accepted when “he raises his hands,” and Allaah is shy to return the hands of His slaves empty when they raise them to Him. The person exclaims, ‘My Lord! My Lord!,’ and the scholars affirm that for a person who repeats the words ‘My Lord! My Lord!,’ it is most likely that his prayer will be accepted. Some go as far as saying, whoever repeats it five times, his prayer is accepted, as in the last few aayahs of Soorah Aaly ‘Imraan. Therefore, the factors which make prayers accepted are all there, so what prevents the prayer from being accepted? It is the occurrence of obstacles and therefore there is no point is exerting effort so long as such obstacles exist. Removal of obstacles needs to happen in order for the prayer to be accepted. The Prophet ﷺ said about the person,
‘… his food is prohibited, his drink is prohibited, his clothing is prohibited, and he has been nourished by what is prohibited; so how could he be answered?’
Therefore, it is incumbent upon a person to be very mindful and cautious that his food, drink and clothes are permissible, and that no doubtful matter enters into what he consumes, let alone the prohibited.