en_tn/mal/03/17.md

They will be mine

"They will be my people"

my own treasured possession

Here "possession" refers to one's personal property. This idea can be expressed with a verb. AT: "they will belong completely to me" (See: rc://en/ta/man/translate/figs-abstractnouns)

I act

This expression refers to the time when Yahweh will judge and punish the rebellious Israelites, giving victory to the faithful Israelites. (See: Malachi 4:1-3)

distinguish between

"see a difference between" or "treat differently"