'Seed' in the Bible

and it happened, as he sowed, some seed fell by the road, and the birds came and devoured it.

He said, "The Kingdom of God is as if a man should cast seed on the earth,

and should sleep and rise night and day, and the seed should spring up and grow, he doesn't know how.

It's like a grain of mustard seed, which, when it is sown in the earth, though it is less than all the seeds that are on the earth,