Tamid, Chapter 3, Mishnah 6. This chapter follows the order of the early morning service in the Beit Hamikdash step by step, and we have now reached the moment just before the korban Tamid is slaughtered. Two kohanim still have work waiting for them inside, and the Mishnah sends them in ahead of everyone else.
"Mi shezacha bedishun mizbeach hapenimi vehamenorah hayu makdimin": the two kohanim who had drawn the lots, one for removing the ash of the golden mizbe'ach that stood within and one for tending the lamps, went in ahead of the others. Since their avodah was scheduled before the slaughter of the Tamid, there was no reason for them to stand and wait; they proceeded into the Heichal, the chamber that housed the menorah and that inner mizbe'ach.
The four vessels
"Ve'arba'ah kelim beyadam": they carried four vessels of the Beit Hamikdash with them. The first was "hateni", the basket used to gather the ashes of the inner mizbe'ach. The second was "hakuz", the jug in which the ashes and the leftover oil of the menorah were collected. And then "ushnei maftechot", two keys, which were needed in order to unlock the doors and gain entry to the Heichal itself.
The Mishnah now describes each of them.
The teni
"Hateni domeh letarkav gadol": the Mishnah likens the teni to a large tarkav, a measuring vessel whose capacity was three kav and whose form was that of a basket with a wide spout. This one was "shel zahav", wrought of gold, and "machazik kabin vachetzi", holding two and a half kav, a bit smaller than the tarkav to which it is compared.
The kuz
"Vehakuz domeh lekiton gadol": the vessel that received the burnt wicks and the surplus oil of the lamps had the appearance of an oversized flask, and it too was "shel zahav", fashioned of gold.
The two keys
"Ushnei hamaftechot": the pair of keys served to open the entranceway of the Heichal, and the two were not of one kind. "Echad yored le'amat hashechi": one of the locks sat on the inner face of the door, beyond the reach of anyone standing outside. A narrow hole had been made in the door, and the kohen would thread his arm through it, sinking in as deep as the armpit, and only from there could he take hold of the mechanism and turn the key to release it.
"Ve'echad pote'ach kevan": the second lock was positioned in the ordinary place, and it opened directly, with no special maneuver and no unusual effort at all.