Agree on an appropriate dower before entering into any kind of marital contract

This hadith from Ibn 'Umar states that the Prophet Muhammad prohibited shighar marriage. Shighar is a type of marriage where two people exchange their daughters or sisters without fixing a dower. This means that one person would give his daughter to another man in marriage and the other man would give his daughter to him in return, but neither party would pay any money as part of the agreement. This practice was seen as unfair and exploitative by the Prophet Muhammad, so he forbade it and instead encouraged couples to agree on an appropriate dower before entering into any kind of marital contract. By doing this, both parties are ensured that they will receive something for their efforts and contributions to the relationship. The lesson here is that fairness should be practiced in all aspects of life, especially when it comes to matters such as marriage which involve two individuals making important decisions about their lives together.