'Leaven' in the Bible

You are to eat unleavened bread for seven days. On the first day be sure to remove all the leaven from your houses, because any person who eats anything leavened from the first day until the seventh will be cut off from Israel.

For seven days leaven is not to be found in your houses. Indeed, any person who eats anything leavened, is to be cut off from the congregation of Israel, whether an alien or a native of the land.

Unleavened bread is to be eaten for seven days, and nothing leavened is to be seen among you, nor is leaven to be seen among you throughout your territory.

"Any grain offering that you bring to the LORD is not to be prepared with yeast, because anything with leaven and honey may not be offered in smoke as an offering by fire to the LORD.

It is not to be baked with leaven. I've given it as their portion out of my offerings made by fire. It's a most holy thing, like the sin and guilt offerings.

Bring two loaves of bread from home as wave offerings made from two tenths of fine flour baked with leaven as first fruits to the LORD.

While you're at it, present a thank offering with leaven, and publicize your freewill offerings, letting everyone hear about it, because this is what you really love to do, you Israelis," declares the Lord GOD.