Few practices have been as important to Judaism as the observance of the Sabbath. Keeping it rightly was so important under the old covenant that one could be executed for working on the Sabbath day, at least under certain circumstances (Num. 15:32–36). For millennia since then, observing the Sabbath has played a key role in Jewish identity. To this day, in fact, there is a tradition among many Jews that the Messiah will come only when all Jews worldwide properly celebrate the Sabbath just once.
The particular concern for Sabbath-keeping among the Pharisees, who were the forefathers of modern Rabbinic Judaism, is evident in today's passage. After all, they would not have criticized the disciples for "doing what is not lawful on the Sabbath" if they thought Sabbath observance was optional for other Jews (Mark 2:23–24). The precise violations of which the disciples were accused appear to have been a combination of traveling too far on the Sabbath and harvesting grain on the Sabbath. As we will see in our study of Mark 2:27–28, these accusations were illegitimate, for Jesus ultimately denied the propriety of the Pharisees' Old Testament hermeneutic (interpretation). First, however, He had to build a case that they read the Sabbath law wrongly, and He did so by appealing to David's example.
During the old covenant, on a table in the Holy Place of the Jerusalem temple sat the "consecrated bread"—also known as "showbread" or "bread of the Presence"—to which Jesus refers in Mark 2:25–26. Ordinarily, this bread was reserved for the priests alone (Lev. 24:5–9). Yet, as Jesus notes, on one occasion during "the time of Abiathar the high priest," the non-priest David and his soldiers were permitted to eat it (Mark 2:25–26). Jesus' reference is to 1 Samuel 21:1–6, which records an episode when David, who was running for his life from Saul, received the showbread from Ahimelech the high priest. Our Lord likely mentions Abiathar and not Ahimelech because Abiathar was more well known and succeeded Ahimelech in the priestly role a er Saul executed Ahimelech for aiding the fugitive David (22:6–23). Jesus means that the incident took place during Abiathar's lifetime, not during his actual high priesthood.
In any case, Jesus' appeal to David's example establishes that rightly understanding the old covenant law requires taking the entire old covenant canon into account. One passage of Scripture is not properly interpreted in isolation but in light of all of Scripture.
One fundamental error that most cults make is to take one passage of Scripture in isolation and exalt it over all others and at the expense of the meaning of other passages. But God has not given us only one passage. He has given us a canon of sixty-six books, and each passage must be interpreted in light of the whole of Scripture. Thus, we become better biblical interpreters the more of the Bible that we know. Let us study the whole counsel of God so that we might rightly understand it.