Numbers 5:15
Then he must bring his wife to the priest. He must also bring an offering for her. It is about 2 quarts of barley flour. He must not pour oil on it or put frankincense on it. That is because it is a grain offering for jealousy. It is a memorial offering that brings sin to mind.
Numbers 5:15, Readable English Bible (READ)
Note: Hebrew: a tenth of an ephah.