Timothy hints to Phillip that Phillip should climb some of the trees on the island in order to harvest some of the coconuts.
Phillip and Timothy are stranded on a tiny island together. Timothy is wise and experienced at all kinds of things, but he is old. Phillip is young and energetic, but he is currently blind. At this point in the story, Timothy has been doing most of the work on the island to ensure their survival. Their diet through this point has basically been anything that the ocean provides. Timothy mentions that the coconuts would be a good dietary supplement. The problem is that Timothy knows that he is too old and weak to climb to that height. Phillip is physically capable of doing the climb, and Timothy hints that Phillip should give it a try. Unfortunately, Phillip is too scared to attempt the climb.