Here "kingdom of heaven" refers to God's rule as king. The phrase "kingdom of heaven" is used only in Matthew. If possible, use "heaven" in your translation. See how you translated this in [Matthew 13:24](./24.md). Alternate translation: "When our God in heaven shows himself to be king, it will be like" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Say "a large amount of flour" or use a term that your culture uses for measuring large amounts of flour. (See: [[rc://en/ta/man/translate/translate-bvolume]])
The implied information is that the yeast and the three measures of flour were made into dough for baking. (See: [[rc://en/ta/man/translate/figs-explicit]])