Hebrew word · H7603

שְׂאֹר

se'or

leaven

The leavening agent: a piece of old, fermented dough (sourdough starter) kept back from one batch to mix into the next. Before commercial yeast this was the only common way to make bread rise. HALOT and BDB both define it as "leaven" in this sense, the substance rather than the bread.

Appears 5 times in 5 verses of the Hebrew Old Testament. ·

What it means

leaven

Abridged from Brown, Driver and Briggs, A Hebrew and English Lexicon of the Old Testament (1906), via STEPBible.org (CC BY 4.0).

In depth

From the study of Exodus 12:15

Range of meaning

The leavening agent: a piece of old, fermented dough (sourdough starter) kept back from one batch to mix into the next. Before commercial yeast this was the only common way to make bread rise. HALOT and BDB both define it as "leaven" in this sense, the substance rather than the bread.

Against the English

"Leaven" (KJV, ESV, BSB) is right. "Yeast" (WEB, NIV, NLT) is understandable, but a modern reader thinks of a packet of dried yeast bought at a shop. Seʾor was a living lump of the household's own dough, often kept going from batch to batch for a long time. Throwing it out meant breaking the household's chain of bread and starting again from nothing.

How it drifted

Modern baking replaced sourdough with commercial yeast, so "yeast" now pictures an ingredient you buy, not the inherited starter in the house.

Used elsewhere in the period

Exod 12:19; 13:7; Lev 2:11 (no seʾor or honey may be burned on the altar); Deut 16:4. The LXX uses zymē, the word that also stands behind "a little leaven leavens the whole lump" (1 Cor 5:6; Gal 5:9). Plutarch (Roman Questions 109) says the Roman priest of Jupiter could not touch leaven because it arises from corruption and corrupts the dough. Some ancient peoples therefore saw fermentation as a form of decay.

Where it appears

Exodus · 3

  1. Exodus 12:15 שְּׂאֹ֖ר leaven

    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.

    Here: The leavening agent itself: a lump of old fermented dough saved from the last baking to start the next batch. This is the thing that has to go.

  2. Exodus 12:19 שְׂאֹ֕ר leaven

    For seven days there must be no leaven found in your houses. If anyone eats something leavened, that person, whether a foreigner or native of the land, must be cut off from the congregation of Israel.

  3. Exodus 13:7 שְׂאֹ֖ר leaven

    Unleavened bread shall be eaten during those seven days. Nothing leavened may be found among you, nor shall leaven be found anywhere within your borders.

Leviticus · 1

  1. Leviticus 2:11 שְׂאֹר֙ leaven

    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.

Deuteronomy · 1

  1. Deuteronomy 16:4 שְׂאֹ֛ר leaven

    No leaven is to be found in all your land for seven days, and none of the meat you sacrifice in the evening of the first day shall remain until morning.

Word data: STEPBible.org (CC BY 4.0), main text only.