I’m not a theologian, but I do know that the Jewish people are famous for giving aid to the sick and supplying help when needed to other nations in, for instance, earthquake rescues, medical needs and so on. We even gave medical assistance to the residents of Gaza before Oct. 7 2023, despite huge logistical problems and existential threats from Hamas. So it seems in practice that we have always considered these works of mercy as mitzvot, regardless of any legal definition. It is just something that Jews do because we are Jews! And now as Catholics, we are doubly obligated. Please forgive me if this is a somewhat naive reply, as I know there are many on this site with greater knowledge than I.
