Is it permissible for a retiree to engage in freelance commercial activity, paying social security installments to receive a retirement pension upon reaching the age of sixty-five, and what is the ruling on this pension?

Social security is permissible under three conditions: the owner's consent, that it is cooperative and not commercial, and that its funds are not invested in haram (unlawful) activities. If the funds are invested in haram, participation is not permissible unless it is mandatory by the state. In that case, one is only allowed to own what was taken from their own funds, and any surplus must be spent on charitable causes.