The following is an excerpt from 'Lange's Commentary on the Holy Scriptures: Critical, Doctrinal, and Homiletical' by Johann Peter Lange:
1. "The general truth lying at the basis of this parable Isaiah, that the culture of the earth reflects that of heaven. The great outstanding features of humanity-the husbandry of God, are reflected in those of earth-the husbandry of man."
2. In accordance with this view a wider bearing might be given to this parable by referring it to the sowing of God's word generally in the world. But evidently the passage applies in a special manner to the foundation of the kingdom of heaven under the New Testament. The sower is Christ, and the seed the gospel. His scattering the seed in such abundance is explained on the ground. (1) of the freeness and fulness of His grace in sowing (ἐν τῷ σπείρειν αὐτόν); (2) of the poor condition of so much of the soil. If it is objected that this would savor of fatalism, we reply,-(1) That the passage under consideration is a parable, and hence does not in every respect adequately express the idea which it is intended to convey; (2) that the difference in the various kinds of spiritual soil is mainly the result of our own doing; (3) that this difficulty is removed by the change which the Lord introduces in the explanation of the picture. Those who received the seed were themselves sowed. The four classes of hearers form at the same time a gradation and a contrast: (1) By the way-side: souls trodden down and beaten down into hard, impenetrable soil by the lowest and meanest kind of worldliness and corruption. In their case the word is caught away even during the hearing of it. (2) Rocky ground, covered by a thin layer of earth: souls all the more enthusiastic in their early ardor, the less solid and settled they are in their personal convictions,-mere weathercocks, turning with every change of wind; the word apparently springing up with marvellous rapidity, but, not having root, withering away in the hour of trial. (3) Soil which might have yielded rich fruit, had it not been covered with thorns: earnest but legal minds, promising but superficial hearers, whose divided heart or worldliness causes them to lose the reward; the word springing up-the stalk and blossom appearing, but the fruit wanting. (4) Lastly, abundant fruit, showing that the soil from which it sprung is not only deep, but that weeds and thorns had been removed: souls whom the hearing of the word leads to its practical understanding, and to growing self-surrender unto the Lord.
The seed of the kingdom of heaven being thus scattered broadcast, it follows, from the character of the soil, that the kingdom of heaven-as outwardly visible-cannot present the picture of a pure and unmixed community of saints.
3. To the Jews, and to mere nominal Christians, this parable conveys the solemn truth that only part of the soil which is sown bears fruit. Of course, anything like an arithmetical calculation of the "fourth part" is out of the question; still, it implies that the number of God's people is small.