Jamieson, Fausset and Brown on Mark 4:8

8. And other fell on good ground, and did yield fruit, &c.--The goodness of this last soil consists in its qualities being precisely the reverse of the other three soils: from its softness and tenderness, receiving and cherishing the seed; from its depth, allowing it to take firm root, and not quickly losing its moisture; and from its cleanness, giving its whole vigor and sap to the plant. In such a soil the seed "brings forth fruit," in all different degrees of profusion, according to the measure in which the soil possesses those qualities. See on Mr 4:20.