BSA_en_tn/2ch/35/06.md

consecrate yourselves

This probably refers to the priests and Levites washing themselves before they did work in the temple.

to do according to the word of Yahweh that was given by the hand of Moses

Here the word "hand" refers to Moses himself. Yahweh used Moses as the agent to deliver his command. This can be translated in active form. Alternate translation: "to obey all of the commands that Yahweh gave to the people through Moses" or "to do everything that Yahweh commanded Moses to tell the people" (See: rc://en/ta/man/translate/figs-synecdoche and rc://en/ta/man/translate/figs-activepassive)