Mark 4:27

And should sleep, and rise night and day, and the seed should spring and grow up, he knoweth not how.

Cross-reference

Ecclesiastes 8:17 declares that man cannot fathom God's work—directly echoing the farmer's ignorance of how the seed grows.

Ecclesiastes 11:5 uses wind and womb growth as mysteries—almost a direct commentary on the farmer's unknowing observation of the seed.

John 3:8 Parallel

John 3:8 compares the Spirit's work to wind—unseen yet effective, exactly paralleling the farmer's ignorance of the seed's growth.

1 Corinthians 15:38 states God gives the seed a body as He chooses—directly paralleling the divine role in the seed's growth that the farmer does not control.