Numbers 5:14-15

14and if jealous feelings come over him and he becomes suspicious of his wife, when she is defiled; or if jealous feelings come over him and he becomes suspicious of his wife, when she is not defiled –

15then 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.