Numbers 15:4; Leviticus 2:1

then che who brings his offering shall offer to the Lord da grain offering of a tenth of an ephah1 of fine flour, emixed with a quarter of a hin2 of oil;

Laws for Grain Offerings

When anyone brings a pgrain offering as an offering to the Lord, his offering shall be of fine flour. qHe shall pour oil on it and put frankincense on it