A fermenting agent (like yeast), which in biblical times was normally added to a batch of bread dough by using an unbaked portion of dough from the previous batch. However, the custom of nomads was to eat unleavened bread, and evidence of this is found in the OT (Gen 19:3
; Judg 6:19
; 1Sam 28:24
). The Festival of Unleavened Bread owes its name to the fact that all leaven was avoided during its seven days (Exod 12:15
) as a memorial of what had happened at the exodus (Exod 13:7-8
). Leavened bread was also prohibited in sacrifices that went on the altar (Lev 2:4
). Leaven was viewed as causing decay and so became a symbol of evil and the corruption of human nature. This idea is reflected in the NT in Jesus’s sayings about the leaven of Pharisees, Sadducees, and Herod (Mark 8:15
) and in Paul’s attack on Corinthian laxity and Galatian circumcising (1Cor 5:6-8
, Gal 5:9
). But the positive concept of leaven as a powerful life force also appears in Jesus’s parable of the growth of the kingdom (Matt 13:33
; Luke 13:20-21
3But he urged them strongly; so they turned aside to him and entered his house; and he made them a feast, and baked unleavened bread, and they ate.
19So Gideon went into his house and prepared a kid, and unleavened cakes from an ephah of flour; the meat he put in a basket, and the broth he put in a pot, and ... View more
24Now the woman had a fatted calf in the house. She quickly slaughtered it, and she took flour, kneaded it, and baked unleavened cakes.
15Seven days you shall eat unleavened bread; on the first day you shall remove leaven from your houses, for whoever eats leavened bread from the first day until ... View more
7Unleavened bread shall be eaten for seven days; no leavened bread shall be seen in your possession, and no leaven shall be seen among you in all your territory ... View more
4When you present a grain offering baked in the oven, it shall be of choice flour: unleavened cakes mixed with oil, or unleavened wafers spread with oil.
15And he cautioned them, saying, “Watch out—beware of the yeast of the Pharisees and the yeast of Herod.”
6Your boasting is not a good thing. Do you not know that a little yeast leavens the whole batch of dough?7Clean out the old yeast so that you may be a new batch ... View more
9A little yeast leavens the whole batch of dough.
The Parable of the Yeast
33He told them another parable: “The kingdom of heaven is like yeast that a woman took and mixed in with three measures of flour until ... View more
The Parable of the Yeast
20And again he said, “To what should I compare the kingdom of God?21It is like yeast that a woman took and mixed in with three measures ... View more