Numbers 12:11

11.And Aaron said unto Moses, Alas! my lord. Although Aaron was aware that, through God’s indulgence, his own punishment was remitted, still he does not cease to consider what he had deserved. For we ought not to wait until God smites ourselves, but since in chastising others He invites us to repentance, although He may spare ourselves, we should profit betimes by their punishments. The disfigurement, therefore, of his sister, alarmed and terrified Aaron, so that, examining his own condition, he acknowledged himself to be deserving of a similar judgment. His humble prayer manifests that those high aspirations were subdued, which had carried him away into unholy jealousy. Moses, who was younger than himself, and whose superiority he just before could not endure, tie now calls his lord, and confesses himself to be subject to his authority and power. Thus the dread of punishment was the best medicine to cure his disease of ambition. In beseeching Moses not to impute his sin to him, he does not usurp for mortal man a right which God by Isaiah claims for Himself alone; (46) but inasmuch as Moses had been injured, he asks his pardon, lest by his accusation he should be brought before the divine tribunal. Where he confesses his own and his sister’s foolishness, he does not extenuate the grossness of his crime, as most people do, when they generally seek to cover their transgressions under the plea of error or thoughtlessness; but it is precisely as if he had said that they were senseless, and out of their minds, as we gather from the next clause, in which he plainly acknowledges their criminality.

By the comparison which he introduces, it is evident that the leprosy of Miriam was of no ordinary kind, for nothing can be more disgusting than the dead body of any abortive foetus, corrupt with purulence and decay.