Numbers 5:15

5:15 then the man must bring his wife to the priest, and he must bring the offering required for her, one tenth of an ephah of barley meal; he must not pour olive oil on it or put frankincense on it, because it is a grain offering of suspicion, a grain offering for remembering, for bringing iniquity to remembrance.

Numbers 5:18

5:18 Then the priest will have the woman stand before the Lord, uncover the woman’s head, and put the grain offering for remembering in her hands, which is the grain offering of suspicion. The priest will hold in his hand the bitter water that brings a curse.