John Gill Bible Commentary

Because they provoked his spirit;.... Though he was a very meek man, meeker than any upon the face of the earth, Num 12:2, yet, being greatly provoked, let fall some passionate and undue expressions: and this was not only his sin, but the fault of those also that provoked him, and with this view it is mentioned. The Targum is, "for they rebelled against his Holy Spirit;'' the Holy Spirit of God, as in Isa 63:10. Jarchi interprets it of Moses and Aaron provoking the Spirit of God; which sense is mentioned, by Aben Ezra and Kimchi; though they seem to prefer the former, and which seems best. Some interpret it of the Israelites, that they caused Moses and Aaron to provoke his Spirit. So that he spake unadvisedly with his lips; that is, Moses spake, saying, Hear now, ye rebels, must we, or "can we", fetch you water out of this rock? Which words were spoken in an angry passionate way, calling them rebels, and expressing diffidence about getting water out of the rock; which was the thing that was so displeasing to God, because they did not believe him to sanctify him in the eyes of the children of Israel, Num 25:10. Jarchi, as before, understands this of God, of his speaking, pronouncing, and declaring, that Moses and Aaron should not bring the congregation into the land of Canaan, Num 25:18, and so the word "unadvisedly" may be left out, and only read, "he spake with his lips"; but the other sense is to be preferred.