Is it permissible to enter into a business partnership where the partner is responsible for financial management and contracts, with the condition that one's share be relinquished and sold to him at the same contribution rate in the event of a problem?

It is not permissible to oblige one partner to sell his share to the other at the same proportion he contributed, because this constitutes stipulating one contract within another, which is impermissible, unless it is a promise separate from the partnership contract. Furthermore, setting a specific price for the share is considered a guarantee for the partner's capital, which is not permissible. Rather, the sale price must be determined by the market value on the day of sale or by what is agreed upon at that time.