זָקֵ֥ן וּנְשׂוּא־פָנִ֖ים ה֣וּא הָרֹ֑אשׁ וְנָבִ֥יא מֽוֹרֶה־שֶּׁ֖קֶר ה֥וּא הַזָּנָֽב׃
Ibn Ezra on Isaiah
The ancient, etc. Now the prophet explains that both head and root signify the old;17The old has here the meaning of chief, which זקנים elders very often has in the Bible. the tail and the rush signify the false prophet.