G-d instructed Moshe and Aharon to speak to the boulder and extract from it water. At this point, Moshe speaks very sharply to Israel, calling them "rebels," and then strikes the boulder. Some commentators said that what Moshe did wrong (I don't like saying that Moshe "sinned") is that he spoke in anger to Israel, and others say that he hit the rock instead of speaking to it. The Maharal of Prague explains that these two things are one: Because Moshe got angry, therefore he hit the boulder instead of speaking to it. "Anger" means a lack of happiness, a lack of emuna and trust in G-d. The Maharal says that joy and faith in G-d always come together.
The Almighty says, "Let the Red Cow come and expiate the sin of the Golden Calf." Yet, this calls for an explanation - What does the statute of the Red Cow have to do with the sin of the Golden Calf? What logical connection is there between the two?
Og king of the Bashan believed that brute physical might is the determining factor in war, and that one who possesses such might is bound to triumph. Yet, in truth, it is the spirit that always triumphs.