http://revach.net/article.php?id=446

Section: Parshas HaShavua   Category: Numbers & Letters
Parshas Chukas: Copper Snakes and Miracles

When Bnei Yisroel were punished with the plague of poisonous snakes, Hashem tells Moshe to make a copper snake and put it on a "Nes" which literally means a high pole. Those who are bitten need to look up at and become healed. Why does the Torah use the word "Nes"? Doesn't Nes mean a "miracle"?

Nature is also a miracle albeit one that we are accustomed to. The same Hashem who commanded oil to light can command vinegar to light. The word for nature "HaTeva" has the same gematria as "Elokim". We call something a "Nes" when it stands out as unusual. Only the supernatural impresses us. Unfortunately the hand of Hashem in all other events that only he orchestrates is lost because of our dull senses. That is why the word we use for miracle is Nes, a high pole. It is an event that causes even the most hardened heart to take notice of the hand of Hashem.

Therefore Hashem tells Moshe put the snake on a high pole. Force Bnei Yisroel to pay attention to Hashem and understand that a plague of snakes although natural can come only from the heavens. Once they understand this important lesson they will automatically be cured.