One of the important topics on the Incident at the Bitter Waters is an issue of trust. Trust is a social construct and thus it only exists insofar we have a certain vision of the other person or, indeed, ourselves. In Erikson’s stages of psychosocial development, the building of trust happens in the first stage, taking place, or not developing within the first two years of a child’s life.
Moses strikes the rock twice and is rebuked by God for not having a sufficient level of trust. Thus, he, together with Aaron, who was also responsible for not properly executing God’s orders, is denied the opportunity to lead the children of Israel in the promised land. So whence does this lack of trust come from? The actual text in Numbers 20:12 states: “Because you did not believe in Me”. The problem at Meribah goes way beyond the current behavior or misbehavior of Moses and Aaron. In Shabbat 97a the sages recall the incident of the burning bush, where Moses is reluctant to return to Jewish people, fearing their lack of trust of belief unto his message (“But, behold, they will not believe me.” Exodus 4:1).
God, however, quite sourly tells Moses to take care of his trust issue first, as the people of Israel are believers and children of believers. Moses, on the other hand, according to God’s promise, one day will fail to believe himself. This is exactly what happened, not once but twice, although the second blow might have been added purely for the theatrical effect.