We know there are Hadeeths that show that our Prophet, sallallaahu alayhi wa sallam, used to take a bath with his wives after ritual impurity. But I don’t understand the reason behind bathing with his wives. One answer to the question could be that same water could be used by both spouses for purifying purposes. But still I feel there is more to it for the spouses bathing at the same place and at the same time. As it is required in our religion to be modest and moral, taking a bath is something that is done alone in a washroom, where no one can see us. But from the Hadeeth, we know that in case of marriage partners, it is permitted. Apart from the fact that it shows nakedness is permissible among the spouses, what benefits could be achieved from them bathing together. Obviously, if our Prophet, sallallaahu alayhi wa sallam, did something, it certainly has advantages, because everything he did was full of wisdom. What did the prominent scholars said about this Hadeeth, as to what could be the reason of Prophet, sallallaahu alayhi wa sallam, bathing sometimes with his wives? What could be the benefits?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

'Aa'ishah said, “I performed Ghusl (i.e. a ritual bath) with the Prophet from the same container.” Besides what you mentioned in the question, among the benefits which the scholars extracted from this narration, is that whenever it is possible for a spouse to teach his wife by action (by demonstrating the act) then this is better. Teaching by demonstration makes the learner understand more than without demonstration. In addition to this, the people are in need of knowing the guidance of the Prophet when he had Ghusl, and no one could know this except through his wives. Therefore, one of the objectives of such Ghusl is this (i.e. teaching his guidance to others).

Allaah Knows best.