John MacArthur, in his NT commentary on Matthew, explains the cultural and historical value of a lump of leavened dough to a new bride in ancient times:
When a Jewish girl was married, her mother would give her a small piece of leavened dough from a batch baked just before the wedding. From that gift of leaven the bride would bake bread for her own household throughout her married life. That gift, simple as it was, was among the most cherished that the bride received, because it represented the love and blessedness of the household in which she grew up and that would be carried into the household she was about to establish.
John MacArthur is the pastor-teacher of Grace Community Church in Sun Valley, California, as well as an author, conference speaker, president of The Master’s College and Seminary, and featured teacher with the Grace to You media ministry.
As women of God, we not only carry with us a legacy--a lump of leavened dough--from our past, but we are granted the responsibility of passing on our own dough--a legacy of love and grace--in such a way as to impart and permeate the generation to come.
Be careful then to bake the best loaf of bread, hiding away within your own heart and the hearts of your household, the truths and blessings of the Kingdom of God.
"Jesus also used this illustration: 'The Kingdom of Heaven is like the yeast a woman used in making bread. Even though she put only a little yeast in three measures of flour, it permeated every part of the dough'" (Matthew 13:33, NLT).