And the LORD spake suddenly unto Moses, and unto Aaron, and unto Miriam, Come out ye three unto the tabernacle of the congregation. And they three came out.

Wesley's Notes

12:4 Suddenly - To stifle the beginnings of the sedition, that this example might not spread amongst the people. Come out - Out of your private dwellings, that you may know my pleasure and your own doom.

Jamieson-Fausset-Brown Bible Commentary

4. the Lord spake suddenly unto Moses, and unto Aaron, and unto Miriam-The divine interposition was made thus openly and immediately, in order to suppress the sedition and prevent its spreading among the people.

Matthew Henry's Concise Commentary

12:1-9 The patience of Moses was tried in his own family, as well as by the people. The pretence was, that he had married a foreign wife; but probably their pride was hurt, and their envy stirred up, by his superior authority. Opposition from our near relations, and from religious friends, is most painful. But this is to be looked for, and it will be well if in such circumstances we can preserve the gentleness and meekness of Moses. Moses was thus fitted to the work he was called to. God not only cleared Moses, but praised him. Moses had the spirit of prophecy in a way which set him far above all other prophets; yet he that is least in the kingdom of heaven, is greater than he; and our Lord Jesus infinitely excels him, Heb 3:1. Let Miriam and Aaron consider whom it was they insulted. We have reason to be afraid of saying or doing any thing against the servants of God. And those are presumptuous indeed who are not afraid to speak evil of dignities, 2Pe 2:10. The removal of God's presence is the surest and saddest token of God's displeasure. Woe to us, if he depart! he never departs, till by sin and folly we drive him from us.