Ver. 18-21. See Poole on "Matthew 13:31", and following verses to Matthew 13:33. They are two parables by which Christ foretells the great success of the gospel, notwithstanding the present small appearance of the efficacy of it.
Related Commentaries of Luke 13:18
Luke 13:18
18 Then said he,Unto what is the kingdom of God like? and whereunto shall I resemble it?