A.T. Robertson Commentary Luke 8:11

"Now the parable is this: The seed is the word of God." — Luke 8:11 (ASV)

Is this (εστιν δε αυτη). Means this. Jesus now proceeds to interpret his own parable.

The seed is the word of God (ο σπορος εστιν ο λογος του θεου). The article with both subject and predicate as here means that they are interchangeable and can be turned round: The word of God is the seed. The phrase "the word of God" does not appear in Matthew and only once in Mark and John (John 10:35), but four times in Luke (5:1; 8:11,21; 11:28) and twelve times in Acts. In Mr 4:14 we have only "the word." In Mr 3:31 we have "the will of God," and in Mt 12:46 "the will of my Father" where Lu 8:21 has "the word of God." This seems to show that Luke has the subjective genitive here and means the word that comes from God.