Maybe his physicality was not as limiting to what he was mentally able to grasp either. In Olam Habah we will all know all the answers, all the different opinions, all the different conclusions. Bayom hahu yiheyeh H' echad ushmo echad. On that day G-d will be One and His Name will be One. After one comes two.
Moshe takes water out of the rock a second time by hitting the rock twice.
ArtScroll takes water out of the rock as well. You'll have to find one to see what I mean because they use the hebrew spelling. To transliterate it all here would be silly. Juxtaposed to the explanationless red heifer is the 'sin' of Moshe upon which the Sha'arai Aharon brings down 25 different explanations of what kept Moshe out of Israel. This whole episode is just a few verses long.