Tosefta for Yoma 88:5

They may enter [the area] between Ulam (=אולם, the hall leading to the Temple interior (see Jastrow)) and the Altar without having washed their hands and feet, the words of Rabbi Meir. And the Sages say, they may not enter. Said Rabbi Shimon the Humble ("הצנוע") before Rabbi Eliezer, "I myself entered [the area] between the Ulam and the Altar without having washed my hands and feet." He said to him, "Who is [God's] beloved, you or the High Priest?" He was quiet. He said to him, "You are ashamed to say that [even] the High Priest's dog is [more] beloved than you." He said to him, "Rabbi, [it is as] you said." He said to him, "They even crack open the head of the High Priest with logs [should he enter the Ulam without washing]. What will you do so the Head of the Temple Guard (בעל הפול) doesn't find you?" Rabbi Yosei says, in the same way that everyone stays away from [the area] between the Ulam and the Altar at the time of the incense [ceremony], so too they stay away at the time of the presentation of the blood of the bull of the anointed Priest [in atonement for] an inadvertent communal sin, and the goats of [an inadvertent communal act of] idolatry, and the blood of the [sacrificial goat of] Yom Kippur. And [even] higher [in holiness than the area] between the Ulam and the Altar [is the area] between the Altar and the Holy. For whereas between the Ulam and the Altar, they may enter [both] to [perform the Temple] service and not to [perform the Temple] service, [between the Altar and] the Holy, they do not enter except to [perform] the service.