This can be stated in active form. Alternate translation: "wafers without yeast which he rubbed with oil" (See: [[rc://en/ta/man/translate/figs-activepassive]])
The word "their" refers to the other offerings that the Nazirite man was told to bring. Often grain offerings and drink offerings were required to accompany other types of sacrifices. The full meaning of this statement can be made clear. Alternate translation: "together with the grain offering and drink offering that Yahweh required to accompany the other offerings" (See: [[rc://en/ta/man/translate/figs-explicit]])