The spell doesn’t put it clearly, but you can rule it in two ways. The fact that it has a verbal component automatically forces your character to say something to make the spell work. You could rule that first, you do some chanting and then your very thoughts become the message that reaches the target, or you could say that the message itself is the material component, but nobody can hear it, well because it is being silenced by magic or because you just mumble and that becomes the message. There are many options.