Which part of the tabernacle was covered with brass instead of gold?
The brazen altar was the part of the tabernacle covered with brass instead of gold. Throughout the tabernacle's construction, wood was covered with gold, symbolizing Christ's humanity and deity, but the brazen altar was the exception, covered with brass.
Les explains that the tabernacle's wood frame was made of acacia wood, which spoke of Christ's humanity in His flesh, and it was covered with gold, which spoke of His deity. He notes that this pattern of wood covered with gold runs throughout the whole construction of the tabernacle, speaking of Christ as both man and God. The one exception, Les points out, is the brazen altar, which was covered with brass rather than gold.