Nachschlagewerk zu Wajikra 16:2

The area between the porch (ulam) and the altar is holier, for [priests] who have blemishes or unkempt hair may not enter it. The Hekhal is holier, for no one whose hands or feet are unwashed may enter it. The Holy of Holies is holier, for only the high priest, on Yom Kippur, at the time of the service, may enter it. Rabbi Yose said: in five respects the area between the porch and the altar is equal to the Hekhal, for those afflicted with blemishes or with a wild growth of hair, or who have drunk wine or whose hands or feet are unwashed may not enter there, and the people must keep away from the area between the porch and the altar when the incense is being burned.