What is the ruling on investing in a commercial project for a fixed percentage of the profits, estimated at 20%, with capital guaranteed and the possibility of its retrieval at any time? Is this considered permissible or impermissible?

It is not permissible to specify a percentage of profit in Mudarabah from the capital. Rather, it must be a common share of the profit, such as half, a quarter, a third, or 20% of the profit. For the Mudarabah contract to be valid, it is stipulated that the money be invested in permissible ventures and that the capital not be guaranteed. This is because Mudarabah is a partnership in which the capital provider contributes their money and the worker contributes their effort. If a loss occurs, the capital provider alone bears it, unless there was negligence on the part of the worker. Furthermore, the share of each party in the profit must be determined by a common percentage, not by a fixed amount or a guarantee of the capital; otherwise, the Mudarabah would be invalid.