In this parsha the subject of anger and its consequences comes up. With the death of Miriam and the fear that the benefits she gave by providing water would end, the tribes once again not trusting in Hashem – how soon we forget the gifts and complain – they and their leaders (here each wearing the color of his tribe) confront Moses and even consider stoning him. Moses had wanted to study with them to give them the confidence that they would be able to transcend their fears by understanding the deep connection we have with Hashem. But when they rebelled against him, Moses too got angry and as we all know hit that rock, and the results of this anger were that Moses was not allowed to enter into the promised land. So, this is a reminder to all of us when we are triggered by hurt and fear to anger that there are unwanted consequences that come with this emotion. There is reference here to the red heifer but it is more a mystery.