Answer
Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, we appreciate your asking this question and invoke Allah Almighty to reward you abundantly for your interest in knowing the teachings of your religion.
It goes without saying that Islam fights all forms of unlawful earnings and requires every Muslim to eat or consume none but what is lawful and pure. A true believer should be keen not to allow any unlawful item to enter his life. He should also advise relatives and friends whose earnings are based on unlawful means and warn them against this.
In his response to the question, the eminent Muslim scholar and renowned da`iyah, Sheikh `Abdel Khaliq Hasan Ash-Shareef, states:
First of all, I would like to state that people are of two types regarding the issue in point:
One whose income is purely of unlawful earnings and one whose income or earnings are mixed with that which is lawful and that which is unlawful. For example, a belly dancer or a prostitute whose only source of income is her job, her earnings are purely haram. However, an employee who additionally does some business based on interest, his income is mixed.
Regarding the person whose earnings are unlawful or mixed, we should differentiate between parents and other people like relatives and friends. This is because parents have a very special status and position. We are ordered to show them respect and be dutiful to them. Almighty Allah says, “And We have enjoined upon man concerning his parents. His mother bears him in weakness upon weakness, and his weaning is in two years. Give thanks unto Me and unto thy parents. Unto Me is the journeying. But if they strive with you to make you ascribe unto Me as partner that of which you have no knowledge, then obey them not. Consort with them in the world kindly, and follow the path of him who repents unto Me. Then unto Me will be your return, and I shall tell you what ye used to do.”(Luqman 31: 13-14)
Again, with respect to parents, people are of two types: those who are dependent on their parents and rely on them in their life, and those independent children who have their own income. If one is still under the guardianship of his parents and still dependent on them for livelihood, costs of living and study, etc., he is allowed to make use of his parents’ earnings for his basic needs, not luxuries. In fact, it may have a deep effect on the father to see his child poor and only fulfill his basic and necessary needs in order to avoid what is haram.
As for the independent child, he should differentiate between having a cup of tea at his father’s house and his father’s giving him a car as a present. Little things are pardoned, but indulging with him in luxuries and accepting luxurious gifts should be avoided.
As for other relatives or friends, the basic rule is that one should not eat with him unless he does so with the intention of advising and reforming him. Therefore, if food is presented to him, he then can participate by taking a small amount in order to have a good relation and reconcile his heart so that the person or relative can accept advice. However, indulging with them in luxurious meals or feasts and other luxuries is not permissible.
In this regard, Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, states,
In his Ihya’ `Ulum ad-Din, Imam al-Ghazali states that if one’s parents’ earnings are unlawful or mixed, then he should avoid eating with them; but if this makes them angry, then he should not agree with them on what is purely haram but should admonish them and forbid them from indulging in such unlawful things, as no creature is to be obeyed in an act entailing disobedience to the Creator. But if the parent’s earnings are doubtful or mixed and he avoids eating with them because of wara` or piety (that is, refraining from what is doubtful for fear of indulging in what is unlawful), one should know that wara` (piety) requires gaining their pleasure, which is obligatory. In such case, if one can, he should politely refrain in a way that does not cause their displeasure; otherwise he should agree but eat a little bit and not indulge in eating. Also, if one’s mother bought her daughter a dress by means of doubtful earnings and she will become angry if her daughter refuses it, then she should accept and wear it in her presence and take it off when she is absent.
Allah Almighty knows best.