They shall not teach (ou mē didaxōsin). Strong double negative (ou mē) with the first aorist active (futuristic) subjunctive of didaskō.
His fellow-citizen (ton politēn autou). See Luk 15:15; Luk 19:14.
Know the Lord (Gnōthi ton kurion). Second aorist active imperative of ginōskō. In the new covenant all will be taught of God (Isa 54:13; Joh 6:45), whereas under the old only the educated scribe could understand the minutiae of the law (Dods). See Paul’s comparison in 2Co 3:7-18.
Shall know (eidēsousin). Future perfect active, old form of oida (note ginōskō just before of recognizing God), one of the rare future perfects (cf. Heb 2:13, esomai pepoithōs).