These notes on Numbers 20:12 are interesting and insightful.

https://enduringword.com/bible-commentary/numbers-20/

"... sins that leaders among God’s people must take special care to avoid:

~Acting rashly at a time of emotional vulnerability; it is possible that Moses suffered from unresolved grief over his sister’s death. 

~Simple disobedience – not doing what God told him to do. 

~Being a bad example – not showing God as holy before the people. 

~Not listening when God wanted to do something different – thinking the miraculous could be made mechanical. 

~Annoyance from wounded personal importance. 

~Taking credit for themselves for God’s work. 

~Thinking God’s work must include something more than a word. 

~Presenting God as angry with His people when God isn’t angry.

~Giving in to personal anger with God’s people. 

~Giving in to fearing the worst about the unbelief and faithlessness of God’s people. 

~Failing to draw on God’s strength to endure until the end. 

~Being a bad illustration of Jesus."

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“Perhaps there is no story in all the Old Testament more searching for all who are called to lead the people of God, than this of the failure of Moses. What he did was most natural. Therein lay the wrong of it.” (Morgan)