Numbers 12:13

13.And Moses cried unto the Lord. The event now proves, what was recently asserted, that Moses was of a meek and gentle disposition beyond all other men; for he is not only ready at once to forgive, but also intercedes with God for them. And thus the presumption of Miriam is best reproved; for the only hope of safety that remains to her is in the dignity of Moses, which of late she could not endure.

From the reply of God, it is manifest that the punishment which she alone had received was intended for the instruction of all. The pride and temerity of Miriam were sufficiently chastised, but God wished it to be a lesson for all, that every one should confine himself to his own bounds. Meanwhile, let us learn from this passage to pay due honor to the judgments of God, so that they may suffice us as the rule of supreme equity. For if such power over their children is accorded to earthly parents, as that they may put them to shame at their will, how much more reverence is due to our heavenly Father, when he brands us with any mark of disgrace? This was the reason why Miriam was shut out for seven days, not only that she might mourn apart by herself, but also that her chastisement might be profitable to all. It is likewise addressed to us, that we may learn to blush whensoever God is angry with our sins, and thus that shame may produce in us a dislike of sin. This special example afterwards passed into a law, as we have already seen, (Deuteronomy 24:9); (47) for when God commands lepers to be separated, He recalls to the recollection of the people what He had appointed with respect to Miriam, lest, if internal impurity be cherished, its infection may spread beyond ourselves.