What is "Kohen ha'Rosh"?
Radak (Melachim II, 25:18): It is the Kohen Gadol, who is the head of the other Kohanim.
What is "Kohen ha'Mishneh"?
Targum Yonasan: It is the Segan. Rashi - he is appointed to serve in place of the Kohen Gadol if he will become Pasul (e.g. Tamei).
What are "Shomerei ha'Saf"?
Targum Yonasan: Amarkelaya 1 . Rashi (here and Melachim II, 12:10): They guard Safei (the gates of) ha'Azarah; the keys of the Azarah are handed over to them. There were seven Amarkelim, for the seven gates of the Azarah (Tosefta Shekalim 2:15).
Radak (Melachim II, 12:10): They guard Klei ha'Bayis. Saf is a general term for Klei Shares.
Radak (Melachim II, 12:10): This is a great Gizbar (overseer of Hekdesh) appointed over others. Targum Onkelos of "v'Nasi Nesi'ei ha'Levi" (Bamidbar 3:32) is 'Amarkelaya d'Memana Al Ravrevei Livai.'
