A.T. Robertson Commentary Luke 8:5

"The sower went forth to sow his seed: and as he sowed, some fell by the way side; and it was trodden under foot, and the birds of the heaven devoured it." — Luke 8:5 (ASV)

His seed (τον σπορον αυτου). Peculiar to Luke.

Was trodden under foot (κατεπατηθη). First aorist passive indicative of καταπατεω. Peculiar to Luke here.

Of the heavens (του ουρανου). Added in Luke.