John 5:10, 15, 18

So the Jews said to the man who had been healed, “It is the Sabbath, and it is not lawful for you to take up your bed.”

The man went away and told the Jews that it was Jesus who had healed him.

This was why the Jews were seeking all the more to kill him, because not only was he breaking the Sabbath, but he was even calling God his own Father, making himself equal with God.