'Seed' in the Bible

As he spake to our fathers, to Abraham, and to his seed for ever.

A sower went out to sow his seed: and as he sowed, some fell by the way side; and it was trodden down, and the fowls of the air devoured it.

Now the parable is this: The seed is the word of God.

It is like a grain of mustard seed, which a man took, and cast into his garden; and it grew, and waxed a great tree; and the fowls of the air lodged in the branches of it.

And the Lord said, If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it should obey you.

Saying, Master, Moses wrote unto us, If any man's brother die, having a wife, and he die without children, that his brother should take his wife, and raise up seed unto his brother.