We tend to think that "unleavened bread" means bread that hasn't risen, but that isn't necessarily the case.Taken from the comments on Gideon's post here.
God did not prohibit Israel from using yeast. What was prohibited was leaven.
The leaven in question was a bit of dough from the previous batch. The dough would be allowed to ferment (thereby producing yeast) and the fermented dough (leaven) would be added to the new batch of dough to make the bread rise. This is still how you make sourdough bread.
But God wanted Israel to make a complete break from Egypt. Therefore, she wasn't allowed to use any of the old leaven -- the stuff from the previous lump -- in the new bread. That's also Paul's point in 1 Cor. 5: you're a new loaf, so get rid of the old leaven.
Unless you're making sourdough bread, you don't use leaven today. That is, you don't use any of the previous dough. Instead, you start afresh (though you do use yeast to make it rise). Therefore, biblically speaking, all of our risen bread (with the exception of sourdough) is unleavened bread and is appropriate for both Passover and the Lord's Supper.
by: John on 2003-03-11 02:56:45
Wednesday, March 12, 2003