What is the religious ruling on the profits generated from investment certificates deposited in the bank, originating from the deceased father's pension? Is it permissible to give from it to poor relatives and orphans if it is considered unlawful? And what is the validity of the fatwa issued by the Egyptian Dar al-Ifta permitting these profits?

Certificates of deposit in usurious banks are forbidden because they involve usury. This is because banks deal with depositors on the basis of a loan contract with interest, not a Mudarabah (definition) (profit-sharing) contract. Usurious interest must be disposed of by spending it on the welfare of Muslims or on the poor and needy, including poor relatives.