This double negative emphasizes that what has been given from above is the only thing that allows Pilate to have power. Alternate translation: "The power you have over me is only what has been given to you from above" (See: [[rc://en/ta/man/translate/figs-doublenegatives]])
The words "from above" are a euphemism for "by God. This can be stated in active form and the one who has given can be specified. Alternate translation: "what God has given you" (See: [[rc://en/ta/man/translate/figs-euphemism]] and [[rc://en/ta/man/translate/figs-activepassive]])