today's other readings are Psalm 95 and Mt. 16: 13-23
It was a very hard time for the Israelites. Wandering in the Sinai wilderness, not knowing exactly when or how they would end up in the Promised Land. As it turned out, it would take 40 years.
At times in those 40 years they had to deal with enemies, as well as the other realities such as hunger and thirst, thirst being highlighted in our reading today.
One may ask, why the punishment for Moses and Aaron in today's reading? The answer lies in what they said to the Israelites. Shall we bring water for you out of this rock?
Of course it was not them who brought out the water. It was God. But they took the credit, and thus they get the punishment.
In the end, all the good we do in our lives of faith, is not our work, but it is the work of God. To God goes the glory, always.