Minecraft wiki entry for Command_blocks_and_functions, associated text: The /say command is extremely useful because it simply prints text into the chat. It may be one of the better uses of the Command Block as you don't need silly signs or long books to show the game rules. Just put a bunch of command blocks in lines with repeaters set to two or three ticks (to avoid spamming players) allowing you to easily remove a chest of books or a large number of signs.