Having concluded His instructions for installing the priests through their special uniforms and installation rites, G‑d taught Moses how to construct the incense Altar. This Altar was placed in the outer chamber of the Tabernacle.
The Inner Life
וְעָשִׂיתָ מִזְבֵּחַ מִקְטַר קְטֹרֶת וגו': (שמות ל:א)
You must make an Altar for burning incense. Exodus 30:1

One reason why the passage about the Inner Altar is placed at the very end of all of the discussions pertaining to the Tabernacle and all that was in it, is in order to indicate that the Inner Altar has a unique status, above and beyond all of the other furnishings of the Tabernacle.

What was different about the Inner Altar was that every other ritual that was performed in the Tabernacle had spectators. When the incense was burned on the Inner Altar, however, there was no one present – only the priest burning it and G‑d Himself. Furthermore, we are taught that it was specifically this private service that caused the Divine Presence to be most felt in the Tabernacle.

This lesson of the incense is very relevant in our modern – and loud – world. The ultimate in holy living, and especially in areas of kindness and charity, is when no one is present – when we exhibit generosity without publicity, purely because it is the right thing to do.1