1. Leviticus 16:17 (ESV)
  2. Exposition

Who was allowed to enter into the Tabernacle?

Leviticus 16:17 (ESV)

17 No one may be in the tent of meeting from the time he enters to make atonement in the Holy Place until he comes out and has made atonement for himself and for his house and for all the assembly of Israel.

Only the High Priest was allowed to enter the Most Holy Place on the Day of Atonement. In addition to that, no other priests were allowed to enter the Tent of Meeting.