We know not how

"The kingdom of God

is as if someone would
scatter seed on the ground,
and would sleep and rise
night and day,
and the seed would sprout and grow,
he does not know how.
The earth produces of itself,
first the stalk, then the head,
then the full grain in the head.
But when the grain is ripe,
at once he goes in with his sickle,
because the harvest has come."

Mark 4:26-29