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Geoff Smith
Unleavened bread was significant when the Isrealites were exiting Egypt quickly and did not have time for the leaven (yeast) to be added to raise the dough.
My opinion only, but another significance to believers is that we now we have become the leaven of His word. Matthew 13 when Jesus talks of the kingdom of heaven being like yeast. We spread the Word and the kingdom of heaven will rise and grow.