A raising agent commonly used in bread. Bread that was required quickly was baked without yeast, as at the first Passover, commemorated annually in the Feast of Unleavened Bread. Although some non-meat offerings contained yeast, it could not be burned on the altar.
Unleavened bread was made without yeast
Exodus 12:39 See also Genesis 19:3; Exodus 12:8–11, Exodus 12:34; Judges 6:17–19; 1 Samuel 28:24–25
Since their dough had no leaven, the people baked what they had brought out of Egypt into unleavened loaves. For when they had been driven out of Egypt, they could not delay and had not prepared any provisions for themselves.
The consumption of yeast was prohibited during the Feast of Unleavened Bread
Exodus 12:14–15 See also Exodus 12:17–20, Exodus 13:3, Exodus 13:6–7, Exodus 23:15, Exodus 23:18, Exodus 34:18; Leviticus 23:6; Numbers 28:17; Deuteronomy 16:1–4; Ezekiel 45:21
And this day will be a memorial for you, and you are to celebrate it as a feast to the LORD, as a permanent statute for the generations to come. For seven days you must eat unleavened bread. On the first day you are to remove the leaven from your houses. Whoever eats anything leavened from the first day through the seventh must be cut off from Israel.
Sacrifices burned on the altar were not to contain yeast
Leviticus 2:11 See also Exodus 29:1–3, Exodus 29:22–24, Exodus 34:25; Leviticus 2:4–5, Leviticus 6:16–17, Leviticus 7:12–13, Leviticus 8:2–3, Leviticus 8:26, Leviticus 10:12; Numbers 6:14–15, Numbers 6:19
No grain offering that you present to the LORD may be made with leaven, for you are not to burn any leaven or honey as a food offering to the LORD.
Some offerings contained yeast
Bring two loaves of bread from your dwellings as a wave offering, each made from two-tenths of an ephah of fine flour, baked with leaven, as the firstfruits to the LORD.
Yeast as an image of the kingdom of God
Matthew 13:33 parallel Luke 13:20–21
He told them still another parable: “The kingdom of heaven is like leaven that a woman took and mixed into three measures of flour, until all of it was leavened.”
Metaphorical references to yeast as something evil
1 Corinthians 5:6–8 See also Matthew 16:5–12 parallel Mark 8:14–21; Luke 12:1–3; Galatians 5:2–12
Your boasting is not good. Do you not know that a little leaven works through the whole batch of dough? Get rid of the old leaven, that you may be a new unleavened batch, as you really are. For Christ, our Passover lamb, has been sacrificed. Therefore let us keep the feast, not with the old bread, leavened with malice and wickedness, but with the unleavened bread of sincerity and of truth.
Related themes
Dictionary of Bible Themes © 1999 Martin Manser, licensed CC BY-SA 4.0, via Bible Aquifer. Formatted for this site, with Scripture from the Berean Standard Bible.