live today under his face

We usually hear the Aaronic blessing as a nice farewell at the end of a service. In Numbers it comes with its own purpose statement, and the purpose is ownership: "So shall they put my name upon the people of Israel."
That is what the lifted face means. It is not a mood. It is a claim. God's name is placed on you, and you walk around carrying it. Heiser points out that Revelation later takes this same idea and inverts it - a rival name, borne on people, marking whose they are. Someone's name is on everybody. The blessing tells you whose is on you.
Scripture links:
- Numbers 6:26-27 - "The LORD lift up his countenance upon you and give you peace... So shall they put my name upon the people of Israel, and I will bless them." - Presence and claim.
- Revelation 13:16-18 - The same name-bearing concept, turned sinister.
You are not walking into today unnamed. His name is already on you.