2 Kings 2:10 in the King James Version
And he said, Thou hast asked a hard thing: nevertheless, if thou see me when I am taken from thee, it shall be so unto thee; but if not, it shall not be so.
Context
9 When they had gone over, Elijah said to Elisha, “Ask what I shall do for you, before I am taken from you.” Elisha said, “Please let a double portion of your spirit be on me.”
10 He said, “You have asked a hard thing. If you see me when I am taken from you, it will be so for you; but if not, it will not be so.”
11 As they continued on and talked, behold, a chariot of fire and horses of fire separated them; and Elijah went up by a whirlwind into heaven.