Genesis 13:15 in the King James Version
For all the land which thou seest, to thee will I give it, and to thy seed for ever.
Context
14 The LORD said to Abram, after Lot was separated from him, “Now, lift up your eyes, and look from the place where you are, northward and southward and eastward and westward,
15 for I will give all the land which you see to you and to your offspring forever.
16 I will make your offspring as the dust of the earth, so that if a man can count the dust of the earth, then your offspring may also be counted.