The Paramathabhanga is a work by the Sri Vaishnava Acharya Vedanta Desikan which refutes rival schools of Indian philosophy, both inside and outside of Hinduism. In this chapter of the Paramatha Bhanga, Vedanta Desikan refutes the Charvaka school, an atheistic school of Indian philosophy. Here is what he says to refute the Charvaka argument that the law of Karma makes no sense because an invisible effect cannot come from a visible cause:
If it be said that in case we accept the principle of adrishta, when there are visible ingredient, there should not be invisible effect (to which they give rise), (then we reply) since such is seen to be the case in the lives of Prahlada and Hanuman and others belonging to their kind, as also in the case of curses etc., it is acceptable to us also.
I'm interested in the part in bold. My question is, what does Vedanta Desikan mean by saying that invisible effects arising from visible causes are seen in the stories of Prahlada and Hanuman? Does he mean that their good deeds were rewarded? Is he referring to Vishnu's acts of saving Prahlada from Hiranyakashipu? And is he referring to Hanuman acquiring magical powers from Devas in his childhood?
Do any commentaries on the Paramathabhanga shed light on this?