What are the limits of a wife's obedience to her husband if he insists on buying a house with an interest-based loan from a non-Islamic bank, and what sin is incurred by the wife if she agrees, and does this affect the upbringing of the children?

Borrowing with usury is Islamically forbidden by the consensus of the Ummah, and it is not permissible to undertake it except in cases of extreme necessity that cannot be averted by any other means. Its prohibition is not linked to the availability of Islamic lending options. Advising the husband and reminding him of the prohibition of usury is obligatory, and if he does not respond, there is no sin upon the wife; for Allah Almighty says: ﴿O YOU WHO HAVE BELIEVED, [HOLD TO] YOURSELVES. NO HARM WILL COME TO YOU FROM HIM WHO GOES ASTRAY WHEN YOU HAVE BEEN GUIDED.﴾ (Al-Ma'idah: 105). Obedience to the husband remains obligatory in marital matters despite his insistence on a usurious loan.