The following is an excerpt from The MacArthur New Testament Commentary on John 5.

Now it was the Sabbath on that day. So the Jews were saying to the man who was cured, “It is the Sabbath, and it is not permissible for you to carry your pallet.” But he answered them, “He who made me well was the one who said to me, ‘Pick up your pallet and walk.’ ” They asked him, “Who is the man who said to you, ‘Pick up your pallet and walk’?” But the man who was healed did not know who it was, for Jesus had slipped away while there was a crowd in that place. Afterward Jesus found him in the temple and said to him, “Behold, you have become well; do not sin anymore, so that nothing worse happens to you.” The man went away, and told the Jews that it was Jesus who had made him well. For this reason the Jews were persecuting Jesus, because He was doing these things on the Sabbath. (5:9b–16)

John’s seemingly incidental note that the healing took place on the Sabbath is in reality the key to this incident. It sets the stage for the open hostility that the Jewish authorities manifested toward Christ. The fury of their opposition, fueled at this pool, would only escalate throughout the remainder of His earthly ministry, finally culminating in His death.

Jesus’ refusal to observe the legalistic and man-made Sabbath regulations of rabbinic tradition was a major point of contention between Him and Israel’s religious establishment (cf. Matt. 12:1–14; Mark 2:23–3:6; Luke 6:1–11; 13:10–17; 14:1–6; John 7:21–23; 9:14–16). In fact, the Lord deliberately chose to heal this man on the Sabbath to confront superficial and bankrupt Jewish legalism. The man’s condition was not life threatening, and he was constantly at the pool. Jesus could have easily chosen another day to heal him. But the Lord not only wanted to show mercy to this man; He also wanted to call the nation to repentance by confronting the self-righteous and unbiblical stipulations that led to their illusion of spiritual life. They had become experts at substituting their traditions for God’s commands (Matt. 15:9).

Observing the Sabbath regulations was central to the legalistic Judaism of Jesus’ day. Gerald L. Borchert observes,

The Sabbath had become a pervading theme in Jewish life.… So significant was the Sabbath that a major section of the Mishna was devoted to Sabbath rules. Sabbath obedience became in fact an eschatological issue because it was thought at least minimally that the coming of the Messiah was linked to the perfect keeping of one Sabbath. The actions of Jesus were thus regarded by Sabbath-oriented Jews as being diametrically opposed to the expectations of the rabbis who probably would have categorized Jesus as an antinomian libertarian. He did not seem to be concerned for the precious rules of the rabbis.

Not only in John, but also in the Synoptics is Jesus portrayed as seemingly unconcerned for the rabbinic traditions about the Sabbath.… The rules of the rabbis were a misunderstanding of God’s design for the Sabbath. The Sabbath was not the means to God’s approval, as the rabbis seem to have suggested. The Sabbath was not merely a rule for humans, but a gift to humans (cf. Mark 2:27). It was to be used to honor God and to benefit his people. More importantly, Jesus was Lord of the Sabbath (cf. Mark 2:28). If, therefore, anyone would have a right to act on Sabbath, it was Jesus. (John 1–11, The New American Commentary [Nashville: Broadman & Holman, 2002], 228–29. Italics in original.)

The Old Testament prohibited working on the Sabbath (Ex. 31:12–14; 35:2), but did not specify exactly what kind of work was forbidden. It seems, however, that one’s customary employment was in view. The Israelites were not to participate in their normal, week-long occupations on the Sabbath day.

But rabbinic tradition went far beyond that, listing thirty-nine forbidden categories of work—including carrying goods. The rabbinic prohibition against carrying loads on the Sabbath was ostensibly based on such passages as Nehemiah 13:15–18 and Jeremiah 17:21–22. Those passages, however, were aimed at individuals who conducted their ordinary business, their livelihood or occupation, on the Sabbath. Thus they did not apply to the healed man, since he did not make his living by carrying his mat.

Nevertheless, it was for his violation of rabbinic (but not biblical) law that the Jews (the religious authorities) confronted the man who was cured. “It is the Sabbath,” they declared to him indignantly, “and it is not permissible for you to carry your pallet.” Instead of rejoicing that he was healed, they castigated him for breaking their trivial rules. They were far more concerned with legalistic regulations than with the man’s well-being (cf. Matt. 23:4)—an attitude for which the Lord sharply rebuked them (Matt. 23:13ff.). The false religion of Judaism, like all false systems, cannot change the inside, so it is left to manipulate life on the outside.

Caught in the act of violating traditional Sabbath regulations, the man attempted to defend himself by shifting the responsibility to Jesus. He replied, “He who made me well was the one who said to me, ‘Pick up your pallet and walk.’ ” His fear of the authorities is in marked contrast to the formerly blind man in John 9, who boldly confronted them (John 9:17, 24–33). As Leon Morris wryly observes, “The man was not the stuff of which heroes are made (The Gospel According to John, The New International Commentary on the New Testament [Grand Rapids: Eerdmans, 1979], 306).

Not to be put off, the authorities immediately asked him, “Who is the man who said to you, ‘Pick up your pallet and walk’?” What man, they demanded, would have the audacity to call for such a Sabbath violation and flaunt the authority of the rabbis? Who would dare to violate the “traditions of the elders” (Mark 7:3), which they equated with the inviolable law of God? Such impudence needed to be dealt with at once. Once again, they proved themselves to be far more concerned with the minutiae of the law than with the weightier matters—such as the mercy that had been shown to this needy individual (cf. Matt. 23:23).

To their disappointment, the man who was healed did not know who it was who had commanded him. The stranger had approached him, healed him, and left without giving him His name. Nor could the man point Him out to the authorities, for Jesus had slipped away while there was a crowd in that place (cf. 8:59; 10:39; 12:36). But Jesus did not abandon this man. Later, He found him in the temple and said to him, “Behold, you have become well; do not sin anymore, so that nothing worse happens to you.” Our Lord’s sobering warning reflects an important biblical truth. Although Scripture is clear that illness is not always an immediate result of personal sin (9:1–3), it also teaches that some sicknesses are directly related to deliberate disobedience. For example, after committing adultery and murder, David cried out, “When I kept silent about my sin, my body wasted away through my groaning all day long. For day and night Your hand was heavy upon me; my vitality was drained away as with the fever heat of summer” (Ps. 32:3–4; cf. Ps. 38:1–8). Along these same lines, Moses warned Israel:

If you are not careful to observe all the words of this law which are written in this book, to fear this honored and awesome name, the Lord your God, then the Lord will bring extraordinary plagues on you and your descendants, even severe and lasting plagues, and miserable and chronic sicknesses. He will bring back on you all the diseases of Egypt of which you were afraid, and they will cling to you. Also every sickness and every plague which, not written in the book of this law, the Lord will bring on you until you are destroyed. (Deut. 28:58–61; cf. Lev. 26:14–16)

Even in the church age, Paul wrote to the Corinthians, “For this reason [because of your sin] many among you are weak and sick, and a number sleep [are dead]” (1 Cor. 11:30).

The most natural understanding of the Lord’s warning, then, is that the man’s illness was the result of specific personal sin on his part. If the man persisted in unrepentant sin, Jesus warned, he would suffer a fate infinitely worse than thirty-eight years of a debilitating disease—namely, eternal punishment in hell.

The man’s response suggests that he failed to heed Jesus’ warning, since he promptly went away, and told the Jews that it was Jesus who had made him well. It is astonishing that he would accept this healing after nearly four decades of terrible distress and then walk away from Jesus and show his loyalty to the Jews who hated Him. This has to be one of the great acts of ingratitude and obstinate unbelief in Scripture. He did not intend to praise or worship Jesus for healing him. Since the Jews had already manifested open hostility toward Jesus (vv. 10–12), it would have been incredibly naïve to think they would now react positively. He further aided their hostility by identifying Jesus. More likely, the man’s actions were a further attempt to defend himself for breaking the Sabbath regulations; he could now answer the authorities’ question of verse 12 by naming Jesus (cf. the discussion of vv. 11–13 above).

The Jews also ignored the miracle, as they always did, so the result was predictable: the Jews were continually (as the tense of the verb makes clear) persecuting Jesus, because He was doing these things on the Sabbath. Not only was He guilty (in their minds) of violating the Sabbath Himself, but even worse, He had incited another to do so. So began their open opposition toward Jesus—persecution that would eventually result in His death.

The die was cast. Jesus had not only confronted Jewish legalism at its very core by disregarding their Sabbath rules, but had also challenged them with His true identity as the Son of God, in whom “all the fullness of Deity dwells in bodily form” (Col. 2:9). As impossible as it is to imagine, the Jews’ opposition to their own Messiah would harden and intensify until they finally were able to satisfy their wicked hearts when they “crucified the Lord of glory” (1 Cor. 2:8).