‘But Jesus answered them, “My Father works even until now, and I work”.
Jesus' reply to the charge of breaking the Sabbath is a powerful one. ‘My Father is still at work, and I also am working'. No one will attack God for working on the Sabbath in maintaining the universe, and performing miracles (‘works until now'), why then should they attack the One Who uniquely works on God's behalf, as the miracle proves? It is interesting to note that when Rabban Gamaliel II, R. Joshua, R. Eleazar ben Azariah, and R. Aquiba were in Rome, around AD 95, they gave as a rebuttal to sectarian arguments evidence that God might do as He willed in the world without breaking the Sabbath because the entire world was his private residence. Thus this may well have been a generally held position in Jesus' day.
The reply linked His work with God's work in a very intimate way. He was saying that He had the same authority over the Sabbath as God had. Because God could work, He could work when He was doing the work of God. His use of the phrase ‘my Father' was also very intimate. He was putting Himself on God's side of reality. The implication was that they should see Him as having a unique relationship with the Father, which put Him above men's interpretations of the Law, an implication that they recognise.
In this way Jesus tried to bring them back to considering the miracle. Here was a work of God. Will they not consider its implications? It demonstrated that God was on His side and was pleased with what He was doing. As Nicodemus had said, ‘No man can do these signs that you do except God be with him' (John 3:2).