Had you been in Moshe’s and Aharon’s shoes, what would you have done at this point? Probably, what most people do: raise your own volume and shout back at them.
What did they do?
What, perhaps, can this verse mean on a deeper level?
Sometimes, when a person feels the need to release their anger, it’s better that they take flight and go to a different location - where they can simmer down - versus staying in the same place and saying things that they will later regret.
A few verses later it says:
When giving guidance to someone, it can be said in a negative or positive way.
Dr. Dovid Lieberman says:
Make sure to criticize the act rather than the person... [Seek Peace and Pursue It, page 59, #5. See also pages 60-62 (Viter Press)] It’s easier said than done. Nevertheless, how do we accomplish this task? He says, ... instead of saying, “You’re incompetent or reckless when you...”, it’s better to say, “You’re such a wonderful person and this behavior doesn’t seem appropriate for someone of your refined character” (ibid.) This training takes practice.
Instead of Moshe saying, “Listen now, O rebels, shall we bring forth water for you from this rock?” He could have rephrased his statement by saying, “Please listen, O dear brothers, shall Hashem bring forth water for you from this rock?”
וַיָּ֨רֶם מֹשֶׁ֜ה אֶת־יָד֗וֹ וַיַּ֧ךְ אֶת־הַסֶּ֛לַע בְּמַטֵּ֖הוּ פַּעֲמָ֑יִם...
And Moses raised his hand and struck the rock twice with his rod...
The staff is a metaphor for the tongue. Sometimes, a person can lash out their tongue at people twice. They say hurtful things which can damage a person emotionally and psychologically. Just like a rock is an inanimate object. There are people that treat others like a rock - as if they have no feelings.
וַיֵּצְאוּ֙ מַ֣יִם רַבִּ֔ים וַתֵּ֥שְׁתְּ הָעֵדָ֖ה וּבְעִירָֽם׃ {ס}
Out came copious water, and the community and their beasts drank.
When a person says negative statements to someone, it can deplete a person of all his motivational energy.
What lesson can we learn from Moshe as a person?
You can be the humblest person on the face of the earth. Be the leader of a nation. Yet, no one is perfect and even leaders do lose their temper. Otherwise, why would the Torah mention this incident?