John Calvin Commentary Exodus 11:8

"And all these thy servants shall come down unto me, and bow down themselves unto me, saying, Get thee out, and all the people that follow thee: and after that I will go out. And he went out from Pharaoh in hot anger." — Exodus 11:8 (ASV)

And all these your servants shall come down. Thus far Moses had reported the words of God; he now begins to speak in his own person and announces that, by Pharaoh’s command, messengers would come from his court who would voluntarily and humbly plead for what he had refused regarding the dismissal of the Israelites.

The great severity of these words inflicted a significant wound on the tyrant’s mind, for it was as if he had said — Thus far I have pleaded with you to allow God’s people to depart; now, whether you want to or not, I will go freely, and not even without a request from you and your followers.

What he then relates, that he went out in the heat of anger,¹³⁹ or in a great anger, shows us that God's servants, even when they truly and faithfully perform their duty, are so disturbed by indignation against sin that they are by no means prevented from being affected by anger. Nor is there any doubt that Moses was thus stirred to anger by the impulse of the Spirit.

Yet, since we are naturally too prone to impetuous passions, we must diligently take care that our indignation does not exceed due bounds. The Spirit awakened this zeal in the heart of Moses, which is mentioned here, but He also moderated it at the same time, so that it would contain no mixture of unregulated passion.

But since it may, and often does, happen that the faithful, when influenced by pious zeal, still do not sufficiently restrain themselves or keep themselves within due bounds, the spirit of gentleness and propriety must be sought from God, which can prevent all excesses.

Yet the anger of Moses is a proof to us that God does not want us to lazily and coldly perform the duties He entrusts to us. Therefore, nothing is more absurd than for certain cynics, while they jokingly and ridiculously philosophize about religious doctrines and sting God’s servants with their laughing and flippant witticisms, to deride their vehemence, which is instead worthy of the highest praise.

¹³⁹ Margin, A. V.