דברי הימים ב לה:ז פירוש: רש״י

And Josiah separated for the members of the people - Heb. ויָּרֶם. An example is (Num. 18: 28): “So shall you too separate (תָּרִימוּ),” an expression of separation.

for all that were present He separated small cattle for the Passover sacrifices for all the Israelites present.

for the number of thirty thousand of small cattle, of lambs, and goats.