Eating from mixed money some of which can be ill-gotten

It is obligatory for a Muslim to try his best to adopt what is lawful in his food, drink, and clothing, because the Prophet (peace be upon him) said to Sa`d ibn Abu Waqqas: (Part No. 22; Page No. 256)  If you earn your money lawfully, your supplication will be answered. It is authentically reported in Sahih Muslim that the Prophet (peace be upon him) said: Allah is good and accepts nothing but what is good. Indeed, Allah commands the believers with what He commands the Messengers and says: O (you) Messengers! Eat of the Tayyibât [all kinds of Halâl foods which Allâh has made lawful (meat of slaughtered eatable animals, milk products, fats, vegetables, fruits, etc.] and do righteous deeds. Verily! I am Well-Acquainted with what you do. He also says: O you who believe (in the Oneness of Allâh - Islâmic Monotheism)! Eat of the lawful things that We have provided you with, and be grateful to Allâh, if it is indeed He Whom you worship. Then, he mentioned a man who had traveled on a long journey, his hair disheveled and discolored with dust and was raising his hands to the sky saying ‘O Lord! O Lord!’ but his food is unlawful, his drink is unlawful, his clothing is unlawful and he grew on what is unlawful. How then can his supplications be answered?” The Prophet (peace be upon him) said: Leave what causes you doubt and turn to what does not cause you doubt. There is no harm for you to remain with your father and brothers and eat from their earnings, as long as you do not know that their earning is prohibited. You will reap much goodness by remaining together with them. If your brothers committed something that Allah (Exalted be He) prohibited, it would be obligatory for you to advise them and instruct them to do good, hoping that Allah (Exalted be He) will guide them through you. (Part No. 22; Page No. 257) May Allah grant us success. May peace and blessings be upon our Prophet, his family, and Companions.