Deuteronomy 21:17

But the first-born, son of the hated one, he doth acknowledge, to give to him a double portion of all that is found with him, for he is the beginning of his strength; to him is the right of the first-born.

Genesis 49:3

Reuben! my first-born thou, My power, and beginning of my strength, The abundance of exaltation, And the abundance of strength;

Genesis 25:31-34

and Jacob saith, 'Sell to-day thy birthright to me.'

Genesis 25:5-6

And Abraham giveth all that he hath to Isaac;

1 Chronicles 5:1-2

As to sons of Reuben, first-born of Israel -- for he is the first-born, and on account of his profaning the couch of his father hath his birthright been given to the sons of Joseph son of Israel, and he is not to be reckoned by genealogy for the birthright,

Psalm 105:36

And He smiteth every first-born in their land, The first-fruit of all their strength,

Treasury of Scripture Knowledge

Summary

But he shall acknowledge the son of the hated for the firstborn, by giving him a double portion of all that he hath: for he is the beginning of his strength; the right of the firstborn is his.

The beginning

The right

Bible References

By giving

Genesis 25:5
And Abraham giveth all that he hath to Isaac;
1 Chronicles 5:1
As to sons of Reuben, first-born of Israel -- for he is the first-born, and on account of his profaning the couch of his father hath his birthright been given to the sons of Joseph son of Israel, and he is not to be reckoned by genealogy for the birthright,

The beginning

Genesis 49:3
Reuben! my first-born thou, My power, and beginning of my strength, The abundance of exaltation, And the abundance of strength;
Psalm 105:36
And He smiteth every first-born in their land, The first-fruit of all their strength,

The right

Genesis 25:31
and Jacob saith, 'Sell to-day thy birthright to me.'