To sanctify God is to make Him holy, i.e., separate from all the false gods; to fail to sanctify God is to make Him common. In being angry with the people (v. 10) and in wrongly striking the rock twice (v. 11), Moses failed to sanctify God. In being angry when God was not angry, Moses did not represent God rightly in His holy nature, and in striking the rock twice, he did not keep God’s word in His economy (see note Num. 20:81b, par. 2). Thus, Moses offended both God’s holy nature and His divine economy. Because of this, even though he was intimate with God and may be considered a companion of God (Exo. 33:11), Moses lost the right to enter the good land.
In all that we say and do concerning God’s people, our attitude must be according to God’s holy nature, and our actions must be according to His divine economy. This is to sanctify Him. Otherwise, in our words and deeds we will rebel against Him and offend Him.