The parable of the leaven. Parallel passage: Luke 13:20, Luke 13:21. The growth of the kingdom regarded in its quiet and secret influence. This is to be ultimately complete and universal. The prophecy is partially fulfilled with every fresh recognition of Christian principles in public opinion, or customs, or laws. For "every thought" shall be brought "captive unto the obedience of Christ" (2 Corinthians 10:5). Another parable spake he unto them; The kingdom of heaven is like unto leaven. This is the only passage where leaven is spoken of with reference to its permeating qualities alone, without any trace of the notion of defilement, which the Paschal and other regulations (Exodus 12:15, Exodus 12:18; Exodus 23:15, Exodus 23:18; Le Exodus 2:11) so readily suggested. Even in 1 Corinthians 5:6 and Galatians 5:9 this connotation of evil is not altogether absent. In Talm. Bab., 'Berach.,' 17a, it is used as a figure of the "evil impulse" within us. Hence some have interpreted it in a similar sense here, and have understood our Lord to be referring to the spread of worldliness in the Church (especially after the conversion of Constantine); but
The parallel passage in Mark 4:33, Mark 4:34 is as follows: "And with many such parables spoke he the word unto them, as they were able to hear it; and without a parable spoke he not unto them: but privately to his own disciples he expounded all things." The same general idea underlies our present verses, but although each evangelist appears to have used the same words as a basis, he has worked them out in his own characteristic way. For while both writers contrast our Lord's treatment of the multitudes and his treatment of the disciples in the matter of parables, St. Mark barely alludes to his using them as a judicial punishment upon the people, and St. Matthew merely hints here at the fact that Christ explained them to his disciples (see further, verse 35b, note).
It will be noticed that our verses have much in common with the thought of verse 10, sqq. It seems just possible that both paragraphs had one common nucleus from which they were each developed. But according to existing evidence, verse 10, sqq., and the parallel passages in Mark and Luke serve to introduce explanatory matter to the disciples, and our present verses with the parallel in Mark to close a series of parables.