He wants to propose marriage to a girl whose father puts his money in the bank
Question

                I am intending to propose marriage to a girl, but I found out that her father puts his money in the bank and he is going to prepare her trousseau using this money. Will this trousseau and furniture be halaal or haraam?.
Praise be to Allah.
      Consuming 
      riba is a major sin and one of the serious sins that incur punishment. 
      Allah says (interpretation of the meaning): “O you who believe! Fear 
      Allaah and give up what remains (due to you) from Ribaa (from now onward) 
      if you are (really) believers.

    279. And if 
    you do not do it, then take a notice of war from Allaah and His Messenger 
    but if you repent, you shall have your capital sums. Deal not unjustly (by 
    asking more than your capital sums), and you shall not be dealt with 
    unjustly (by receiving less than your capital sums)”

    [al-Baqarah 
    2:278-279]

    And the 
    Messenger of Allaah (peace and blessings of Allaah be upon him) cursed the 
    one who consumes riba and the one who pays it, the one who writes it down 
    and the two who witness it, and he said: they are all the same. Narrated by 
    Muslim 1598. 

    But dealing 
    with a person who consumes riba is permissible. The Prophet (blessings and 
    peace of Allah be upon him) dealt with the Jews although they consumed riba. 
    What is haraam with regard to the wealth of one who consumes riba is the 
    extra money obtained through riba only; the rest of his wealth -- if it is 
    from a halaal source -- is halaal. 

    Shaykh 
    al-Islam Ibn Taymiyah (may Allah have mercy on him) was asked about those 
    whose wealth is mostly haraam such as tax collectors (referring to the maks, 
    a haraam levy or tax), those who consume riba and so on, as well as those 
    who practice haraam professions such as those who make images of animate 
    beings, astrologers and the helpers of oppressive rulers. Is it permissible 
    to buy food from them or not? 

    He replied: 
If their wealth consists of both halaal and haraam, then dealing with 
    them is a grey area; it cannot be ruled to be haraam unless it is known that 
    he is giving him something that it is haraam to give, and it cannot be ruled 
    to be halaal unless it is known that he is giving him something halaal. If 
    most of it is halaal, then it cannot be ruled that it is haraam to interact 
    with him; if most of it is haraam, it was said that it is halaal to interact 
    with him and it was said that rather it is haraam. 
    
    With regard to 
    the one who deals with riba, the majority of his wealth may be halaal, 
    unless it is known that it is not halaal for some other reason. That is 
    because when he sells 1000 for 1200, it is only the additional amount that 
    is haraam. 

    If his wealth 
    consists of both halaal and haraam and they are mixed, the halaal part of it 
    cannot be ruled to be haraam; rather he may take the proportion that is 
    halaal, as in the case where there are two partners and the wealth of one of 
    them is mixed with the wealth of the other, then it should be divided 
    between the two partners. The same applies with regard to the one whose 
    wealth is mixed between halaal and haraam; the portion that is haraam should 
    be taken out and the rest is halaal for him. And Allah knows best. End 
    quote. 

    Majmoo’ al-Fataawa, 
    29/272-273 

    Shaykh 
    Muhammad ibn ‘Uthaymeen (may Allah have mercy on him) favoured the view that 
    wealth that is acquired by haraam means, such as riba, earnings of a female 
    singer, selling drugs and bribes is only haraam for the one who acquires it; 
    as for the one who takes it from him for a permissible reason, such as if he 
    spends it on his children and his wife, or on a gift or payment for work and 
    so on, it is halaal for the one who takes it. 

    He (may Allah 
    have mercy on him) said: 

    Everything 
    that is acquired by haraam means is haraam and does not benefit the one who 
    acquired it, and if he spends it he will not be blessed in it and if he 
    gives it in charity it will not be accepted from him, and if he leaves it 
    behind, it will be his provision for the Hell fire. 

    But with 
    regard to the one to whom he gives that thing, it is not haraam for him, 
    because the prohibition is connected to the way in which it was acquired, 
    not to the wealth itself. Everything that is haraam because of the way in 
    which it was acquired is only haraam for the one who acquired it in that 
    way, but for the one who takes it by permissible means from the one who 
    acquired it, it is not haraam for him. But as for that which is haraam in 
    and of itself [such as stolen wealth or wealth acquired by force], it is 
    haraam both for the one who acquires it and for others. End quote. 

    Fataawa 
    Noor ‘ala al-Darb, 
    13/179 

    He also said: 

    There is 
    nothing wrong with a person accepting zakaah or donations from riba-based 
    banks, because he is receiving it by lawful means, and the sin is on the 
    bank for acquiring it by means of riba. The evidence for that is the fact 
    that the Messenger (blessings and peace of Allah be upon him) accepted gifts 
    from the Jews and he accepted invitations from the Jews, although it is well 
    known that the Jews consumed riba and acquired wealth by unlawful means. 

    Similarly he 
    interacted with the Jews in Khaybar, i.e., he gave them some of the palm 
    trees and crops on the basis that they would have half and the Muslims would 
    have half, although it was well known that they consumed riba.  

    Hence you may 
    follow a useful principle: If someone acquires something by any permissible 
    means then the sin of the one who acquired it by haraam means is not passed 
    to him, because it is haraam because of the way in which it was acquired, so 
    it is haraam for the one who acquired it in an inappropriate manner. But if 
    you know that this wealth is the property of so and so, such as if a thief 
    stole a sheep and brought it to you as a gift, then it is not permissible 
    for you to accept it from him, because you know that this sheep belongs to 
    So and so. But if something is haraam because of the way in which it was 
    acquired, it is permissible for the one who takes it by lawful means. End 
    quote. 

    Liqa’ al-Baab 
    al-Maftooh, 
    27/140 

    Based on that, 
    there is nothing wrong with proposing marriage to this girl, if she is 
    religiously committed and of good character, and it does not matter that her 
    father puts his money in riba-based banks and will supply his daughter’s 
    trousseau from this wealth. The sin of that haraam wealth is on her father 
    only, and there is no sin on her or on you because of that, in sha Allah. 

    You have to 
    advise her father and tell him not to do this evil thing; you should explain 
    that riba is devoid of blessing and it will be a cause of loss and shame on 
    the Day of Resurrection. 

    For more 
    information please see the answer to question number
    105827 and
    45018 

    And Allah knows best.