This parable stresses the extensive ultimate consequences of the kingdom that would be out of all proportion to its insignificant beginnings.
"Whereas the parable of the mustard seed answers the question of whether the phase of the kingdom planted by Jesus would survive, the parable of the leavening process answers how."548
Some interpreters have understood yeast as a metaphorical reference to evil.549However not all uses of yeast in the Old Testament carry this symbolic meaning (e.g., Lev. 7:13; 23:15-18).550
This parable stresses the hidden internal change taking place in the kingdom between its inception in Jesus' ministry and its final form when the kingdom will cover the earth in the Millennium (cf. 5:13).
"The manifestation of the presence of the kingdom in some form in the Church age is clearly taught in the parables of the mustard seed and the leaven . . ."551
The fact that a woman put the leaven in the meal is probably an insignificant detail of the parable as is the amount of flour. Three satas of flour (about three-fifths of a bushel) is the amount of flour that a housewife baked into bread for an average family.552
"Practical applications of this parable to present readers can include the following. First, believers should depend on what God is doing through His Spirit in the present age. Second, Christians should be suspicious of any man-made, externally influenced institutional structures that say they are the manifestation of God's kingdom, Third, believers must be cautious about setting dates and presuming the arrival of the kingdom since the parable gives no hint as to when the permeation ends. Fourth, Jesus' followers can be confident that regardless of any current perspectives, the kingdom of God has a glorious future."553