 He believed that Onkelos's Aramaic was an artificial construct, a combination of Eastern and Western dialects of Aramaic.The major commentary on Targum Onkelos is "Netinah LaGer" written by Nathan Marcus Adler.According to scholars, Targum Jonathan found in the Chumash was not written by Jonathan ben Uzziel, who refer to it instead as Targum Pseudo-Jonathan.