Thou hast answered right (orqw apekriqh). First aorist passive indicative second singular with the adverb orqw. The answer was correct so far as the words went. In Mark 12:34 Jesus commends the scribe for agreeing to his interpretation of the first and the second commandments. That scribe was "not far from the kingdom of God," but this lawyer was "tempting" Jesus. Do this and thou shalt live (touto poiei kai zhsh). Present imperative (keep on doing this forever) and the future indicative middle as a natural result. There was only one trouble with the lawyer's answer. No one ever did or ever can "do" what the law lays down towards God and man always. To slip once is to fail. So Jesus put the problem squarely up to the lawyer who wanted to know by doing what. Of course, if he kept the law perfectly always, he would inherit eternal life.