David. R. Goodworth explores saying 2.5/Th24 from his book 'The Gospel of Thomas: Evolution'.

His disciples said, “Show us the place where you are, for it is necessary for us to seek after it.” He said to them, “Those that have ears, let them hear. There is light within a person of light, and they become light to the whole world. If they do not shine, they are darkness (there is darkness).”