JMNT(i)
28 Now while approaching, one of the scribes (experts in the Law; Torah interpreters; scholars; theologians), hearing their discussing and questioning together [and] seeing (perceiving) that He beautifully gave a discerning answer to them, made inquiry upon Him, "Which and of what sort is [the] foremost (= most important) implanted goal (impartation of the finished product within; inward directive) of them all?"
29 So Jesus gave a decided reply to him, "Foremost (= Most important) is, 'Be habitually listening and hearing [and, thus, obeying], O Israel, [the] Lord [= Yahweh] [is] our God. [The] Lord [Yahweh] is (continually exists being) one. [note: the Sh’ma]