Hebrews 9:6-8

6Now when these things had been thus prepared, the priests always went into the first part of the tabernacle, performing the services.

7But into the second part the high priest went alone once a year, not without blood, which he offered for himself and for the people’s sins committed in ignorance;

8the Holy Spirit indicating this, that the way into the Holiest of All was not yet made manifest while the first tabernacle was still standing.