Rashi on Numbers 18:9/רש"י על במדבר י״ח:ט׳

1מן האש FROM THE FIRE — i.e., after the burning of the portions given over the fire. (The words are taken to mean: from the time when the fire has operated).

2כל קרבנם EVERY OFFERING OF THEIRS — for instance the sacrifices of communal feast offerings.

3מנחתם חטאתם ואשמם EVERY MEAL OFFERING OF THEIRS, AND EVERY SIN OFFERING OF THEIRS, AND EVERY GUILT OFFERING OF THEIRS — all these offerings should be understood in their usual meanings.

4אשר ישיבו לי WHICH THEY SHALL RENDER (more lit., which they shall return) UNTO ME — This refers to property wrongfully taken from a proselyte (which, when he has no legal heir, reverts to the priests; cf. Rashi on v. 8) (Sifrei Bamidbar 117:2; Zevachim 44b).