When a thought is expressed in speech, the vibration of the sound has a considerable power to bring the most material substance into contact with the thought, thus giving it a concrete and effective reality.
Sound always has a power; it has much more power than men think. It may be a good power and it may be a bad power. It creates vibrations which have an undeniable effect. It is not so much the idea as the sound; the idea too has its own power, but in its own domain – whereas the sound has a power in the material world.
I think I have explained this to you once; I told you, for example, that words spoken casually, usually without any reflection and without attaching any importance to them, can be used to do something very good. I think I spoke to you about “Bonjour”, “Good Day”, didn’t I? When people meet and say “Bonjour”, they do so mechanically and without thinking. But if you put a will into it, an aspiration to indeed wish someone a good day, well, there is a way of saying “Good Day” which is very effective, much more effective than if simply meeting someone you thought: “Ah! I hope he has a good day”, without saying anything. If with this hope in your thought you say to him in a certain way, “Good Day”, you make it more concrete and more effective.