The first-fruits of thy grain, of thy new wine, and of thine oil, and the first of the fleece of thy sheep, shalt thou give him.

then it shall be, in the day that he causeth his sons to inherit that which he hath, that he may not make the son of the beloved the first-born before the son of the hated, who is the first-born:

but he shall acknowledge the first-born, the son of the hated, by giving him a double portion of all that he hath; for he is the beginning of his strength; the right of the first-born is his.