On Rosh Hashana night we do a strange thing: we eat all sorts of different fruits, as well as fish and maybe even the head of a lamb. On each of these foods we say a special yehi ratzon. One may wonder, what exactly are we trying to accomplish when we eat these fruits? Is it supposed to be some sort of tefillah, or is there some other reason for it?
The source for eating the special foods is the Gemara in Kerisus 6a. The Gemara first establishes that there is an idea called simana, which will be explained later. It goes on to say now that we have determined that there is such an idea of simana, one should eat the following fruits, and begins to list them.