Yoma, Chapter 4, Mishnah 5. Continuing the theme of the previous mishnah, which distinguished between what was done on every other day and what was done on Yom Kippur, our mishnah lists further distinctions of this kind in the service of the Kohen Gadol.
Going up the ramp and coming down from it:
"Bechol yom kohanim olim bemizracho shel kevesh veyordin bema'aravo" - when the kohanim went up to the altar, they would ascend on the eastern side of the kevesh (the ramp) and descend on its western side.
"Vehayom kohen gadol oleh be'emtza veyored be'emtza" - on Yom Kippur the Kohen Gadol would go up in the middle of the ramp and come down in the middle.
"Rabbi Yehudah omer: le'olam kohen gadol oleh be'emtza veyored be'emtza" - according to Rabbi Yehudah, it was not only on Yom Kippur; the Kohen Gadol always walked in the middle. The reason for walking in the middle is to display the honor and the affection of all Israel, whose agent the Kohen Gadol is, and therefore he is permitted to conduct himself as a member of the household before the Holy One, blessed is He - as one who is familiar and at home there - going up and coming down in the middle.
Sanctifying the hands and feet:
"Bechol yom kohen gadol mekadesh yadav veraglav min hakiyor" - on every other day the Kohen Gadol would sanctify his hands and feet from the kiyor, the water basin from which all the kohanim washed their hands and feet.
"Vehayom mikiton shel zahav" - on Yom Kippur he would use a special golden vessel, designated for him alone.
"Rabbi Yehudah omer: le'olam kohen gadol mekadesh yadav veraglav min hakiton shel zahav" - according to Rabbi Yehudah, the Kohen Gadol always sanctified his hands and feet from that same special golden vessel, and would not join the other kohanim to wash from the kiyor.
In summary: our mishnah lists two further distinctions between an ordinary day and Yom Kippur - going up and coming down the ramp (on its sides as opposed to its middle), and sanctifying the hands and feet (from the kiyor as opposed to a golden vessel) - and in both cases Rabbi Yehudah holds that this was the Kohen Gadol's practice always, because of the honor and affection of Israel, whose agent he is, and because he is like a member of the household before the Holy One, blessed is He.