I will make your offspring like the dust of the earth, so that if anyone could count the dust, then your offspring could be counted. (NIV)
And I will make your descendants like the dust of the earth, so that if a man could count the dust of the earth, then could your descendants also be counted. [Gen. 28:14.] (AMP)
And I will make thy seed as the dust of the earth: so that if a man can number the dust of the earth, then shall thy seed also be numbered. (KJV)