Moses has a lot on his plate at the moment – and now on top of it all he finds his leadership challenged by his own brother and sister! Ostensibly their grievance is his second wife (has Zipporah died?), who is a foreigner and not even of Abrahamic descent. (Perhaps Miriam wanted to see herself as Israel’s ‘first lady’!) But the real reason is simple jealousy; they are both older than Moses and resent being in the shadow of their ‘upstart’ younger brother.
Moses is entitled to feel threatened (their grumbling is sowing seeds of disunity, and undermining his authority), but he doesn’t take any action himself. As a leader, he is neither arrogant nor overbearing; for there is nothing like a close encounter with the living God to make one humble! It is God who steps in swiftly to nip this bitterness in the bud by summoning Aaron and Miriam to judgement and striking Miriam (presumably the chief instigator) with leprosy for seven days. Having coveted the place of highest prestige, she is forced out of the community altogether for a while – giving her time to reflect on the gruesome consequences of jealousy and resentment.
Moses was no ordinary prophet or leader. The intimacy of his relationship with God was unique (he saw God’s ‘form’, though never His face), and the revelations that he received were not one-way messages but a true conversation. These unusual privileges were the result not only of the unique role he had been called upon to fulfil, but also of the extraordinary diligence with which he carried out his commission. So it was a serious matter to speak against God’s faithful steward… and should we not be all the more willing to submit to the authority of His Son (Hebrews 3:3-6)?