What is the Islamic legal ruling on differentiation in division and expenditure between two wives, one of whom resides in the husband's home country with the children, and the other resides with him in his country of employment, given the disparity in living conditions and income, and the husband's estimation for the first wife exceeding the ordinary expenditure?

A husband must be just among his wives regarding lodging, and there is no difference between those who live with him and those who live away from him. He must divide his time among them in a way that does not cause him undue hardship.

Ibn Qudamah stated that if a husband has wives in two different cities, he must be just between them by going to the absent wife on her designated days, or by bringing her to him so they can be together. If it is difficult to divide the nights equally, he can make the period a month, or more, or less, depending on what is possible and the proximity of the two cities.

The husband must be just between his wives, or appease and reconcile with the distant one.

As for maintenance (nafaqah), it is obligatory to be just in providing the essential maintenance. There is no objection to increasing maintenance for some of them according to their needs.