Husband asking his wife how she disposed of the mahr
Question

                Does the husband have the right to question his wife and ask her how she spent the mahr that belongs to her? My husband is asking about every part of my mahr, great and small, because he divided the mahr into two parts, one part for me and the other to prepare for marriage and buy clothes.
Praise be to Allah.It is not 
    permissible for a husband to question his wife about the mahr which he gave 
    to her, because this is her right and a debt on him which he has to give to 
    her. 
In return 
    for this small amount of money which Allaah has granted to the woman, the 
    right of qiwaamah (being in charge, being the protector and maintainer) is 
    taken from her and given to her husband. So his spending on her is in return 
    for something very precious and the mahr and spending on her is in return 
    for that qiwaamah. Allaah says (interpretation of the meaning): 
“Men are 
    the protectors and maintainers of women, because Allaah has made one of them 
    to excel the other, and because they spend (to support them) from their 
    means”
[al-Nisa’ 
    4:34]
Imam 
    al-Tabari (may Allaah have mercy on him) said: 
“Men are the 
    ones who are in charge of their womenfolk, disciplining them and making them 
    fulfil their obligations towards Allaah and towards themselves. ‘Because 
    Allaah has made one of them to excel the other’ means, because Allaah 
    has given men an advantage over their wives because of the mahr which they 
    give to them, and because they spend on them from their own money, and they 
    take care of them. This is the way in which Allaah has caused them to excel 
    them. Hence they are in charge of them and women are expected to obey their 
    husbands. 
Tafseer 
    al-Tabari, 5/57 
So the mahr is the woman’s right, just 
    as qiwaamah is the man’s right. Just as she should not disobey him because 
    of that qiwaamah, so he should give her her rights. 
Men must 
    fear Allaah with regard to their wives’ mahr and give them their mahrs. For 
    women are weak, so men should give them their rights. 
Allaah says 
    (interpretation of the meaning): 
“O you 
    who believe! Fulfil (your) obligations”

    [al-Maa'idah 5:1]
And indeed the marriage 
    contract is one of the most important contracts which the Muslims are 
    obliged to fulfil. 
It was 
    narrated that ‘Uqbah ibn ‘Aamir (may Allaah be pleased with him) said: The 
    Messenger of Allaah  (peace and blessings of Allaah be upon him) said: 
    “The conditions which most deserve to be fulfilled are those by means of 
    which intimacy becomes permissible to you.”
(Narrated by 
    al-Bukhaari, 2520; Muslim, 2542) 
So long as a 
    woman has taken possession of this money in this manner, her husband has no 
    right to force her to spend it in a particular way, unless she is spending 
    it on something haraam, in which case he has the right to stop her from 
    spending it in haraam ways. 
Our advice to you is to deal with your husband gently and calmly when he questions you about the mahr, lest a dispute concerning this matter be the cause of letting the Shaytaan come between you, especially when you are at the beginning of your married life, which should be based on harmony and tolerance on both sides towards any shortcomings or transgressions on the other side.  We ask Allaah 
    to decree for you a happy life filled with obedience to Allaah and following his laws. And Allaah knows best.