Is it permissible to benefit from the profits of an investment that was later discovered to be unlawful, given the impossibility of withdrawing the principal, and the need for these profits to pay the dowry for marriage?

It is impermissible to invest in websites that finance robots for advertising companies. This is due to the violation of the conditions for sound investment, as the capital is guaranteed, and there is no agreement on a known percentage of profit from the capital. Furthermore, the advertising field may involve promoting prohibited content.

However, if you are forced to wait a period to receive your money, and profit results from that, there is no harm in benefiting from this profit, especially given the need for it and the ignorance of its prohibition when entering into the transaction. This is based on the Almighty's saying: ﴿So whoever receives an admonition from his Lord and desists, he may have what has already passed, and his affair is left to Allah. But whoever returns [to interest] - those are the companions of the Fire; they will abide eternally therein.﴾ [Al-Baqarah: 275].

Shaykh al-Islam Ibn Taymiyyah, may Allah have mercy on him, said: "As for what is undoubtedly clear to us: what was taken by misinterpretation or ignorance, then in this case, what has already passed is his, without doubt."