tree of life. Genitive of cause (App-17) = the Tree supporting and continuing the life which had been imparted. Compare Gen_3:22. Hence "the bread of life", Joh_6:48, Joh_6:51, Joh_6:53.
midst. Compare Rev_2:7.
knowledge = sense or perception (Gen_12:12. Son_6:11. Isa_59:8).