Matter had mass, and mass pulled on everything, including light. Matter could produce or absorb light, while its gravity could shape it. But gravity couldn't really slow light down, when it escaped the field the light continued to race along, just as it had before falling into matter's grasp. Only its path had changed.
Where photons came from when light was emitted still couldn't exactly be explained. No electron or proton could be broken down into a photon. Matter could convey, contain, or release energy, but it wasn't changed by the transmission, just as light wasn't changed by the interaction.