Is the husband entitled to refuse making up the days he spent with his first wife on a treatment trip that occurred on the day of the second wife's turn, knowing that he had promised her to make them up, and that she had previously waived her right to overnight stays when she visited her family? And what are the rulings regarding a polygamist husband traveling with one of his wives for her needs, to the exclusion of the other?

The husband must be just between his wives in terms of division [of time]. It is not permissible for him to travel with one of them for a temporary journey unless the others consent or by drawing lots. However, if the husband travels with one of his wives due to her need, he is not obligated to seek the consent of the others. Nevertheless, he must compensate the second wife for the duration he spent with the wife he traveled with, unless the second wife waives her right.