Lit., should have cast, the aorist tense, followed by the presents sleep and rise (καθεύδῃ and ἐγείρηται). The whole, literally, “As if a man should have cast seed into the ground, and should be sleeping and rising night and day.” The aorist tense indicates the single act of casting; the presents the repeated, continued sleeping and rising while the seed is growing.
Seed (τὸν σπόρον)
The seed; that particular seed which he had to sow. Such is the force of the article.