In the door of the tabernacle, where they stood without, not being admitted into the tabernacle, as Aaron used to be; which is noted as a sign of God's displeasure.
Related Commentaries of Numbers 12:5
Numbers 12:5
5 And the LORD came down in the pillar of the cloud, and stood in the door of the tabernacle, and called Aaron and Miriam: and they both came forth.