For seven days no leaven may be found in your houses; for anyone, a resident alien or a native, who eats leavened food will be cut off from the community of Israel.
You shall not offer me the blood of sacrifice with anything leavened, nor shall the sacrifice of the Passover feast be kept overnight for the next day.
He spoke to them another parable. “The kingdom of heaven is like yeast that a woman took and mixed with three measures of wheat flour until the whole batch was leavened.” The Use of Parables.