Deuteronomy 21:17
but he shall acknowledge the firstborn, the son of the unloved, by giving him a double portion of all that he has, for he is the firstfruits of his strength. The right of the firstborn is his.
Genesis 49:3
"Reuben, you are my firstborn, my might, and the firstfruits of my strength, preeminent in dignity and preeminent in power.
Genesis 25:31-34
Jacob said, "Sell me your birthright now."
Genesis 25:5-6
Abraham gave all he had to Isaac.
1 Chronicles 5:1-2
The sons of Reuben the firstborn of Israel (for he was the firstborn, but because he defiled his father's couch, his birthright was given to the sons of Joseph the son of Israel, so that he could not be enrolled as the oldest son;
Psalm 105:36
He struck down all the firstborn in their land, the firstfruits of all their strength.