New Defender's Study Bible Notes
20:8 Take the rod. This was not the rod of judgment, with which Moses had smitten the rock almost forty years before. Water from that rock had followed them as a perennially flowing stream through all their wilderness wanderings. The rod mentioned here was Aaron’s rod that budded (Numbers 17:10; 20:9), implying resurrection instead of judgment.
20:8 speak ye unto the rock. This rock was a high craggy rock (in Hebrew cela), in contrast to the small rock (in Hebrew tsur), which had been smitten before (Exodus 17:6).
20:11 he smote the rock. Once again the Lord miraculously provided water out of the rock for the horde of Israelites (see note on Exodus 17:6 for the first instance). However, this time Moses disobeyed God by smiting the rock twice instead of speaking to it once. Worse than this, he was now so used to having the Lord perform miracles for the people through him that he took the credit (“must we fetch you water”–Numbers 20:10). It was for this reason that God would not allow him to cross the Jordan. “Ye believed me not, to sanctify me in the eyes of the children of Israel” (Numbers 20:12).