The Bnei Yisroel were bitten by deadly snakes. So Hashem told Moshe to put a copper snake on a high pole, and anyone who looks at it will be healed. The Ramban says that this was a ness b’toch ness: a double Ness. Medically, a person bitten by a snake shouldn’t see the snake, or even hear the word “snake” (this can make things worse), and here both were Davka done, and this became their Refua! Why a double Ness? We see how the Torah wants to give us a message that Tevah is total baloney!
So the next time you have an illness, Chas V'shalom, and you go to a doctor, remember how easily Hashem can cure you! And the same with Parnasa. Look how water can come out of a rock by mere words! A rock symbolizes something hard (“hard like a rock”) and water means softness. Moshe Rabeinu was a kevad peh u’kevad lashon v’arel sefasayim: three different types of speech impediments. Just what a leader cannot have! This is to show that Tevah is baloney, and it’s all just Hashem.
