John Calvin Commentary Exodus 2:12

"And he looked this way and that way, and when he saw that there was no man, he smote the Egyptian, and hid him in the sand." — Exodus 2:12 (ASV)

And he looked this way and that way. From this it more clearly appears that Moses came with the design of helping his unhappy brothers, and of relieving and assisting them, since, by killing the Egyptian, he avenged an injury done to an individual, yet one that affected the whole nation.

But although he was inspired by the Holy Spirit with special courage for this act, it was still accompanied by a weakness, which shows that he did not undertake without hesitation what he yet knew to be his vocation. For Stephen (Acts 7:25) testifies that Moses was not driven by rash enthusiasm to slay the Egyptian, but acted because he knew he was divinely appointed to be the avenger and deliverer of his nation. Still, he looked around to see if anyone saw him, and dared not punish the wrongdoer except by a secret blow. Thus, we perceive that he was not as bold as he should have been, and that he had to struggle against his timidity. Again, we gather from his hesitation that his faith was weak, so we must not suppose that it was praised by the Apostle because it was absolutely perfect.

First, then, let us conclude that Moses did not rashly resort to the sword, but was armed by God’s command. Conscious of his legitimate vocation, he rightly and judiciously assumed the role God assigned to him. From this it follows that private individuals would act improperly, and would by no means be supported by his example, if they sought to suppress wrongdoing by force and arms. To this extent, we should imitate Moses in giving aid to the suffering and oppressed, as far as our means allow, and in not being afraid to incur the ill-will of the wicked when we oppose their oppressions. However, we must leave it to the judges, who are invested with public authority, to draw the sword of vengeance. If these judges do not offer their aid to the innocent when they are unjustly treated, all we can do is lament; for not even Moses would have been allowed to proceed further unless he had been the appointed avenger and deliverer of the people.

Regarding the fear by which he betrayed his timidity and his current unpreparedness for fulfilling his office, let us learn that the obedience of the saints, though stained by sin, is still sometimes acceptable to God through mercy. Therefore, although the weakness of the flesh is a hindrance to us in performing our duty, let us still not cease to struggle against it. For our assurance of this should greatly encourage us, convinced that pardon is ready for our hesitation, if we do not yield to it.