See these parables explained in the notes at Matthew 13:31-32.

The kingdom - is like a grain of mustard seed - See on Matthew 13:31 (note).

Then said he, unto what is the kingdom of God like?.... The same with the kingdom of heaven, in Matthew 13:31 and so the Ethiopic version reads it here, "and whereunto shall I resemble it?" of this way of speaking; see Gill on Mark 4:30.

Then said he, Unto what is the kingdom of God like? and whereunto shall I resemble it?

13:18-21 For notes on the parables of the Mustard Seed and Leaven, see Mt 13:31-33.

13:18 Mt 13:31; Mr 4:30.

Lu 13:18-30. Miscellaneous Teachings.

18-21. mustard seed . leaven-(See on [1657]Mr 4:30-32). The parable of "the Leaven" sets forth, perhaps, rather the inward growth of the kingdom, while "the Mustard Seed" seems to point chiefly to the outward. It being a woman's work to knead, it seems a refinement to say that "the woman" here represents the Church, as the instrument of depositing the leaven. Nor does it yield much satisfaction to understand the "three measures of meal" of that threefold division of our nature into "spirit, soul, and body," (alluded to in 1Th 5:23) or of the threefold partition of the world among the three sons of Noah (Ge 10:32), as some do. It yields more real satisfaction to see in this brief parable just the all-penetrating and assimilating quality of the Gospel, by virtue of which it will yet mould all institutions and tribes of men, and exhibit over the whole earth one "Kingdom of our Lord and of His Christ." (See on [1658]Re 11:15).

13:18-22 Here is the progress of the gospel foretold in two parables, as in Mt 13. The kingdom of the Messiah is the kingdom of God. May grace grow in our hearts; may our faith and love grow exceedingly, so as to give undoubted evidence of their reality. May the example of God's saints be blessed to those among whom they live; and may his grace flow from heart to heart, until the little one becomes a thousand.