Deuteronomy 21:17
But he shall acknowledge the son of the hated, the first-born, to give to him the portion of two in all that shall be found to him; for he is the beginning of his strength; to him is the judgment of the first-born.
Genesis 49:3
Reuben, my first-born, thou my strength, and the beginning of my strength, the abundance of elevation, and the abundance of might
Genesis 25:31-34
And Jacob will say, Sell this day thy birth-right to me.
Genesis 25:5-6
And Abraham will give all which is to him to Isaak.
1 Chronicles 5:1-2
And the sons of Reuben the first-born of Israel, (for he the firstborn; and in his defiling his father's bed, the birth-right was given to the sons of Joseph the son of Israel; and not to be enrolled for the birthright
Psalm 105:36
And he will strike every first-born in their land, the first-fruits to all their strength.