The relationship between a husband and wife is based on trust. Hadrat Musleh Mau‘ud ra explained:
In marriage, the shari‘ah has emphasized fear of Allah. This is because marriage is based on trust. The man completely trusts the woman and the woman completely trusts the man. They both have each other’s wealth and honor in their hands. They can give each other peace, or if they want, they can harm one another as well. Thus, this is the one relationship in the world that functions without laws. There are laws about it in Islam, but those laws are about initial intentions or disorders, not about the period in between. Rather, the area in between is based on complete trust.
1. rukhsati, or “sending off,” occurs when the groom and bride leave the wed- ding venue together [Publisher].
(Khutbat-e-Mahmud, vol. 3, Khutbat- e-Nikah, p. 427)
Trust is such a powerful force that even in the absence of other conditions, it can create a deep love between people. For example, soldiers in combat develop a profound love for one another because they unconditionally entrust their lives to one another. Love is founded on trust, and in the absence of trust, love cannot exist.
When deciding on a spouse, we find out about the person as best as we can, and we pray to Allah Almighty for guidance through istikharah. Once we decide to marry someone, because of the closeness of the relationship, we cannot help but entrust ourselves to them. The Holy Prophet sas stated:
The most important of the trusts in the sight of Allah on the day of judgment is that a man goes to his wife and she goes to him, (and the breach of this trust is) that he should divulge her secret.
(Sahih Muslim, Book 16, Hadith 146).
He sas also stated:
The most wicked among the people in the eyes of Allah on the Day of judgment is the man who goes to his wife and she comes to him, and then he divulges her secret.
(Sahih Muslim, Book 16, Hadith 145)
Furthermore:
When a woman tells her friends about her moments of intimacy with her husband, the angels send their curses on her.
(Khutbat-e-Mahmud, vol. 3, Khutbat-e-Nikah, p. 430).
This is an enormous amount of trust that a husband and wife place in each other, and this mutual trust and intimacy is what develops a deep connection between the couple from the start of the marriage.
If we feel uneasy about our future spouse to the extent that we feel the need to draft a prenuptial agreement about finances, then how can we bring ourselves to entrust ourselves so intimately to them? Prenuptial agreements are not forbidden, but they are not preferred because an ideal relationship of love cannot be properly founded without trust.
At another place, Hadrat Khalifatul-Masih II ra has stated:
The relationship of a husband and wife is extremely important, but it is not with conditions. People generally place conditions that the dowry should be this much and allowance should be this much, but relationships do not remain right like this.
(Khutbat-e-Mahmud, vol. 3, Khutbat-e-Nikah, p. 430)