2 Kings 2:9

And it came to pass, when they were gone over, that Elijah said unto Elisha, Ask what I shall do for thee before I be taken away from thee, some last favor. And Elisha said, I pray thee, let a double portion of thy spirit be upon me, the reference being to the right of the firstborn, who received twice as much of his father's goods as the rest of the children, Deuteronomy 21:17. Elisha's request, as the spiritual son of Elijah, was that he might get a greater share of his spirit than any other prophet of his time.