John Calvin Commentary Numbers 20:10

"And Moses and Aaron gathered the assembly together before the rock, and he said unto them, Hear now, ye rebels; shall we bring you forth water out of this rock?" — Numbers 20:10 (ASV)

And Moses and Aaron gathered the congregation together. There is no doubt that Moses was perplexed between hope and doubt, so that, although he entrusted the event to God, he was still to some extent oppressed with anxiety. For he would never have been so ready and prompt in obeying, especially in such an unusually arduous matter, if he had been without faith. He and Aaron had recently hidden themselves in alarm; it was, therefore, a task of no small difficulty immediately to call the people, from whom they had fled, and voluntarily to face their madness.

Thus far, then, we see nothing but a readiness to obey, combined with magnanimity, which deserves no common praise. But since the unbelief of Moses is condemned by the heavenly Judge, in whose hands is the sovereign power, and at whose word we all stand or fall, we must acquiesce in His sentence. We hardly perceive anything reprehensible in this matter, yet, since God declares that the fall of Moses displeased Him, we must abide by His decision rather than our own. And from this, too, let us learn that our works, on the surface of which nothing but virtue is apparent, are often full of secret defects, which escape the eyes of men, but are manifest to God alone.

If it is asked in what respect Moses transgressed, the origin of his transgression was unbelief. For it is not permissible, when this type of sin is expressly referred to in God's answer, to imagine that it was anything else. But it is doubtful at what point he was unbelieving; unless it is that, in asking whether he could bring water out of the rock, he seems to reject as impossible and absurd what God had promised to do.

And, in fact, he was so entirely preoccupied with considerations of their rebelliousness that he did not acknowledge the grace of God. He inquires whether he shall bring water out of the rock, whereas he ought to have remembered that this had already been permitted to him by God. It was fitting for him, then, confidently to assert that God had again promised the same thing, rather than to speak with hesitation.

Others think that he sinned because he was not content with a single blow, but struck the rock twice. And this perhaps arose from distrust. But the origin of the fault was that he did not simply embrace God’s promise and strenuously carry out the duty assigned to him as an evidence of his faith. Although, therefore, his striking the rock twice might have been a sign of his lack of confidence, it was still only an aggravation of the evil, and not its origin or cause.

Thus, then, we must always return to this: that Moses did not give God the glory, because he considered what the people had deserved rather than estimating the power of God according to His word. And this, too, his previous reprimand denotes, when, in accusing the Israelites of rebellion, he shows, indeed, that he was inflamed with holy zeal; yet, at the same time, he does not rouse himself with suitable confidence for their conviction. Indeed, in a way, he confesses that the power of God fails beneath their wickedness. Thus it is said in Psalm 106:32-33,

“That it went in with Moses for their sakes, because they provoked his spirit, so that he spoke with his mouth:”¹⁰⁹

For the Prophet does not excuse Moses there; but shows that as a consequence of the people's wickedness, he was carried away by reckless fervor, so as to deny that what God had promised would take place. From this let us learn that, when we are angered by the sins of others, we should beware lest a temptation of an opposite kind should take possession of our minds.

¹⁰⁹ A. V., “He spoke unadvisedly.”“He spoke unadvisedly.”