Are customs duties imposed on goods purchased for personal use, not for trade, religiously binding, and what is their reference in the Sunnah and the opinions of the Tabi'in, knowing that the people of Shu'ayb imposed customs duties of 10% which was forbidden, and is it permissible to pay them from bank interest?

The fundamental rule regarding customs duties and taxes is their prohibition, as they constitute devouring people's wealth unjustly. However, they are permissible in exceptional circumstances. This applies to what a person buys for themselves or for trade, regardless of whether the amount is small or large. It is not permissible to pay them from usurious earnings because by doing so, the payer is redeeming their own money and right. The condition for disposing of usurious earnings is that the owner does not benefit from them.