Matthew 13:33

Another parable spake he to them: The kingdom of heaven is like leaven, which a woman took and covered up in three measures of flour, until the whole was leavened.

1 Timothy 4:4

For every creature of God is good, and none to be rejected, if used with thanksgiving:

Treasury of Scripture Knowledge

Summary

Besides the cakes, he shall offer for his offering leavened bread with the sacrifice of thanksgiving of his peace offerings.

Bible References

Leavened

Matthew 13:33
Another parable spake he to them: The kingdom of heaven is like leaven, which a woman took and covered up in three measures of flour, until the whole was leavened.
1 Timothy 4:4
For every creature of God is good, and none to be rejected, if used with thanksgiving: