Note 3 at Joh 7:21: Prior to this instance, Jesus had already performed two recorded healings on the Sabbath day: (1) the impotent man at the pool of Bethesda (Joh 5:2-15) and (2) the man in the synagogue who had a withered hand (Mt 12:9-13, Mr 3:1-5, and Lu 6:6-10; see note 5 at Joh 5:9 for a list of other healings Jesus performed on Sabbaths). Joh 7:23 makes it clear that He must have been referring to one of these two instances (i.e., "I have made a man every whit whole on the sabbath day.") Since John's Gospel was written before the four Gospels were put together into the Bible, it is probable that Jesus was referring back to the healing of the man at the pool of Bethesda (Joh 5:2-15). Otherwise, John would have provided some explanation. Also, Mr 3:7 would make us believe that the healing of the man with the withered hand took place somewhere in Galilee and not here in Jerusalem, as did the healing of the impotent man at the pool of Bethesda (Joh 5:2). Therefore, Jesus speaking in Jerusalem would reference the healing that He had performed there in Jerusalem.

Notice that the healing at the pool of Bethesda had taken place one and a half years earlier, and the Jews were still marveling at it.