One of the earliest rabbinic texts describes the objectives of a Torah teacher in the following way: “The sages said three things… ‘Be very careful in judgment, raise up many disciples, and make a fence around the Torah.’” (Mishnah, Avot 1:1) The first two instructions are easily understood. But what are these “fences around Torah” that ought to be built?
Like a physical fence, a fence built around the Torah is a protective enclosure around God’s commandment; an extra layer of rules. In theory, one would first have to break the “fence” and only then fall into a transgression of the actual commandment of God.
We read in Matthew 5:27-28: “You have heard that it was said, ‘You shall not commit adultery’; but I say to you that everyone who looks at a woman with lust for her has already committed adultery with her in his heart.” Yeshua quotes the original commandment (“Do not commit adultery!”), follows it by the introductory phrase - “but I say to you” and stating the appropriate fence (“Don’t lust in your heart!”). The logic is simple: if one would not lust in thought, surely one would not sin with one's body.
Of course, Jesus was sometimes highly critical of Pharisaic fences, concerned that they sabotaged the deeper meaning of the Torah that Jesus rose to defend (Mark 7:14-23). Yet when asking whether Jesus also built "fences" around the Torah, we must respond in the affirmative - He absolutely did.
If we read the Bible without understanding it's essential Jewishness, then we're really only getting part of the story.