Likewise, you will know that your offspring will be manifold and your progeny will be like the grass of the earth
Other versions
King James Version
Thou shalt know also that thy seed shall be great, and thine offspring as the grass of the earth. English Standard Version
You shall know also that your offspring shall be many, and your descendants as the grass of the earth.New International Version
You will know that your children will be many, and your descendants like the grass of the earth.